Most of our roof repair work on tile roofs involve either just cleaning up the old loose ridge capping and doing a ‘re-point” – or removing all the old bedding and re-bedding back the old ridge capping onto fresh mortar… followed by pointing with Flexipoint.
The ridge capping is held in position on a ‘bed’ of cement mortar. This is the bedding part.
Then when the bedding has set, a thin layer of pointing is applied over the exposed edge of the bedding. This is the pointing part.
The series of You tube videos below provides a more thorough look at what bedding and pointing is all about:
Firstly, the ridge capping is held down and supported by a “BED” of (sand and cement based) mortar. Unfortunately, the bedding will crack as it naturally shrinks and it does not bind the ridge capping very well. Also, the colour of the bedding does not blend in with the colour of the roof tiles or the ridges. And this is where the pointing comes in…
In the (not too distant) past, the pointing was just a thin layer of oxide coloured sand/cement. The ‘cement’ pointing was put together relying on the skill of the roofer and the thin layer had a good chance of sticking onto the bedding without cracking.
Then ‘flexible pointing’ was introduced. One of the first in the market was “FLEXIPOINT”.
With age and movement on the roof, the bedding (and attached pointing) would start to crack – and the ridge capping will then start to dislodge itself and sometimes slide off the roof. This is when the roof has to be “repointed” – to maintain the ridge security. Usually, only the very loose bedding is removed and fresh bedding installed locally to support the ridge capping. Then the rest of the existing (sometimes cracked) bedding is prepared to receive the new pointing.
Sometimes, when a main (horizontal) ridge has been laid without weep holes, A re-point will involve removing all the ridges and the old bedding.
This is to allow for the ridges to be freshly bedded to allow for weep holes to be correctly installed.
The video below shows the preparation work required just prior to the repointing process:
Once the old bedding has been prepared, it is repointed with flexible pointing. There are many brands of flexible pointing available nowadays – and we have used many of them. Nowadays, we have gone back to the original “FLEXIPOINT” – it just seems to work a bit better for us…
An old You tube video that I made a few years ago shows how the pointing is applied:
Flexible pointing is leaps and bounds ahead of the oxide cement pointing that exists on all old roofs. It sticks a lot better, has some flexibility against cracking – and is actually designed to be an alternative to mechanical anchoring of ridge capping onto the roof. It is pretty strong stuff that is very difficult to remove.
…But preparation is still the key – since even the stickiest compound will not stick to an un-prepared surface. Then it is in how the pointing is applied. The combination of the two will determine how effective (and the life) of the repointing job.
You can also see my blog post on ridge capping repair work and my old youtube video below for a bit more information on ridge capping repair work:
Below (in the video) is what your ridge capping should look like after they have been prepared for re-pointing, then re-pointed with “Flexipoint”:.
Is it okay to use flexi point in a 5-10 millimetre gap between slate and a colourbond valley to block a small leak. Will it adhere properly and hold over time? Thanks Paul Jackson
Paul,
Flexipoint will bridge a 10mm gap and if applied correctly, will stick quite well and hold over time.
However, I I not so sure that it will do much for your leak – if you are just going to fill the gap under the slates to the valley. This is meant to be left open to drain water out.
Jack
Hi, how long should bedding and pointing last? I had my terricotta tile roof rebedded and pointed in 2009 and it’s cracking on the ridges, particularly in the meter closest to the gutters.
Hi Louise,
Many years ago, when I was starting up in the roofing business, I remember an old roofer telling me that “.. a tile roof needs a repoint every 15 years…”.
In my experience, this ‘old timer’ is pretty much correct.
There are certain areas of ridging that suffers more from tile movement (due to un-anchored cut tiles). The bottoms of hips and the top of valleys are two of these areas.
A good roofer will prepare the bedding a bit better so that the pointing has a better chance of bonding to the edges of the capping and to the tiles. This will lead to a longer lasting pointing job.
Hope this helps.
Jack
I’m doing some renovations and need to remove a section of ridge capping to access the structure – it is only about 3 years old and adhered quite well. Are there any tricks to getting the ridge capping off without breaking it?
Hi Wayne,
You can try this:
Get a chisel. A cold chisel or an old wood chisel.
Cut into the pointing along the bottom edge of the ridge capping (hammer and chisel trick).
Also cut into the pointing at the collars.
Once you have done enough cutting along the bottom edge of the capping, you will find that you can get the chisel further into the bedding and the pressure will start lifting the cap off. (a bit of levering helps also).
Good luck.
Jack
Hi, I have a couple of capping tiles coming loose from the hips,(the mortar bedding is completely loose and coming away from the tiles) right next to the gutters on a couple of corners of our house. I picked up some Dunlop pointing from Bunnings and I said I needed to re bed the capping also, the lady helping me said I can just use the pointing mix as bedding as well. Would that be ok or would you recommend mixing up some mortar and using that as the bedding? Also, I’ve seen your video where you put drainage holes in the base of the mortar, do you put the drainage holes in the pointing as well and do you put them in the hip capping or just the ridge capping?
Many thanks,
Colleen
Hi Colleen,
It depends on how loose the bedding is and also the ‘shape’ of the bedding under the starters (the pointy ridges) and the adjacent capping at the hips.
If the bedding is quite loose and there is ‘bulky’ bedding (from previous repairs) at the bottom of the hips – then I would recommend removing the old bedding and replacing it with fresh bedding. This will make for a cleaner job and have a much better chance for the pointing to bind the corners together.
Pointing is very ‘flowing’ and it will ‘slump’ if you try to use it as bedding. It will not ‘stand up’ and support the capping.
If the bedding is slightly loose (and in good ‘shape’), then you can enlarge the crack between the bedding and capping by chipping the thin wedge away. Then apply the pointing. Enlarging the crack allows for more surface area for the pointing to bind the old bedding and the sides of the capping together.
Application of pointing to achieve a smooth and clean finish takes years of practice (and even then, some tilers are more skilled than others at pointing).
So, don’t be too hard on yourself if the end result is not very ‘professional’ looking.
All the best…
Jack
Hi Jack,
In your opinion, is it possible for a roof to require rebed and re-pointing just 3 years after it had been previously repaired and re-pointed? taking into consideration, there has been no trees or other heavy objects/debris nearby to cause damage.
Thank you
Hi Mel,
When I was starting out, an old roofer told me that a roof should be re-pointed every 15 years.
Flexible pointing can start peeling off the edge of the ridge capping after a year or so – if it has not been applied correctly.
The bedding should remain solid – even if the pointing starts to fail.
In my experience, the old timer is pretty accurate with his 15 years….
Jack
Hi jack
It’s only been a few years and we are having to get our roof re-pointed. The roofer quoted and said he would Rebed were needed and re-point. He has only removed some of the pointing and said he doesn’t remove it and redo it if it’s okay. Is this standard practice and will the new re-pointing adhere properly to the old stuff? Just not sure if he is doing a good job or not.. thanks
Hi Michelle,
Generally, a roof can be re-pointed a couple of times before it gets too awkward to point and a fresh start (removal of capping and bedding all the ridge capping on new bedding).
During re-points, removal of local bedding and pointing (that is very loose) is the usual preparation work before the fresh flexible pointing is applied.
The main purpose of the pointing is to cover the bedding and to form a ‘bind’ between the capping and the roof tiles. Some local peeling of the new pointing can happen – but it may not necessarily mean that the whole roof needs to be re-pointed again. Unless you have blocked (or absent) weep holes, the peeling does not affect the waterproofing of the roof…
Hope this helps.
Jack
Hi Jack
I just had a couple of roof tiles I need to re-bed. Can I just use the pointing cement to do re-bedding so that I can do all in one hit?
Many thanks!
Peter.
Hi Peter,
You will find that the pointing material is not stiff enough to ‘stand up’ and support the ridges. You will need to bed with a sand/cement mix first and then point after the bedding has been smoothed off and is stiff enough….
Hi Jack,
Is it possible to just replace 2 separate ridge caps rather than removing the whole load and placing it with mortar? I have few caps which care cracked and wondering if I have to redo the whole lot?
Hi Nagzy,
If you can carefully remove the cracked ridge capping and replace them with EXACTLY the same sized (same brand and manufacture period) ridge, then you can usually get away from a full re-bed. You will still need to point the replaced ridges with flexible pointing – and also ensure that there are clear weep holes (if the ridge capping is on a horizontal ridge line).
Otherwise, it is best to remove the bedding locally and re-bed locally.
Hope this helps.
Jack
Hi
I have a single level 4 bedroom house with Terracotta tiles. It is 24 years old. Never been rebedded or repointed. No leaks but I have just noticed that the mortar pointing on a verge over the part of the house which goes over the patio entrance at the front of the house has broken away from a board under the tiles leaving a gap. I have also noticed some of the ridge caps have small holes here and there where mortar has come away from the edge of the ridge cap.
Looking at getting quotes to inspect the whole roof and repair where necessary.
Can the repointing just be done where the mortar is either weak or come away or is it necessary to completely rebid and repoint?
Thanks
Hi Steve,
My take on re-bedding and re-pointing is this:
– The sole purpose of the bedding (sand/cement mix) is to hold the ridge capping in position and to provide a surface for the application of the pointing.
– The sole purpose of the pointing is to bind the edge of the ridge capping to the surface of the roof tile (and also to provide a cosmetic coloured finish on the edge of the ridges.
– There are some roofers who advocate that a ridge capping repair should be a full re-bed (remove all the ridge capping and the old bedding and starting again) followed by a re-point. I disagree. There is no technical need for it. If the old bedding is holding the ridge cap in position and it has sufficient surface area to allow for the application of the flexible pointing ….. then it is doing its job.
– The bottoms of the hips usually suffer from a lot of movement and cracking of the bedding. In this instance, I support the full re-bedding of the bottom ridge caps on a hip to enable a better bind of the pointing to prevent future slippage.
– elsewhere along the hips, there will be local gaps if the old bedding has dislodged. Pointing will not fill large gaps. Therefore local insertion of bedding mortar is needed to fill in the gaps prior to the pointing process.
– On the horizontal ridges, we have to be mindful of the need for weep holes. For most concrete roof tiles and terracotta roof tiles that have a cut course under the capping, weep holes are necessary. Any re-pointing will need to involve re-establishment of existing weep holes. Or, if no weep holes are present, then the horizontal ridges have to be fully re-bedded with weep holes before pointing.
Hope this makes things a bit easier to understand…
Jack
Thanks Jack
I have been told that I will need the roof pressured cleaned with a rotary brush cleaner before repointing is done. The tiles are 24 year old unglazed terracotta Monier. They are quite dirty and have lichen in lots of areas. I have some concerns about pressure cleaning as there is no sarking under the tiles. I am not concerned about the appearance only the practicality of ensuring my roof does not leak. Is it reasonable to only get the ridge caps cleaned? I will also need repointing on verges.
Also should the roofer remove all the old mortar pointing before repointing with flexipoint?
Thanks
Hi Steve,
I have not seen anyone just pressure clean the ridge caps. It would have the same possibility of leakage during cleaning as a roof clean (but to a lesser amount obviously).
We normally steel brush the lichen off before pointing…. concentrating on the edge of the ridge and the top of the tile.
Remember that the main purpose of the pointing is to hold the ridge to the tile roof by binding the edge of the cap to the top of the tile. So, the two most important areas to clean off is just the thin edge of the side of the capping and the small area on top of the tile along the edge of the bedding.
The cleanliness of the bulk of the bedding is not that important. It could be full of Lichen and the pointing can go over it (in theory)…
It is the same with old bedding/pointing. If any old mortar gets in the way of the two critical areas, they should be removed. Otherwise, it is not that important.
Hope this helps.
Jack
Many thanks Jack
I totally agree with your recommendation. It makes no sense to pressure clean if you haven’t first repointed. Otherwise you are increasing the likelihood of water getting into the roof cavity. Obviously you would need to wait some time after repointing before you could pressure clean.
I think it is great that you are sharing your knowledge.
Do you recommend any roof repair/tiling repair company in Melbourne?
Hi Chris,
Sorry, I don’t mix with a lot of roofers and I do not have anyone I know in Melbourne.
There must be some good ones there. It just takes a bit of hunting down.
All the best.
Jack
Hi Jack, can you advise if the ridge caps at the bottom of the hip should be secured with nails? We are in the process of getting quotes here in South Australia for a concrete tiled roof and have been told various things eg nailing or expansion joints, to fix the problem so were not sure who to use and what is the best method. Thanks in advance.
Kind regard
Deb
Hi Deb,
Different states in Australia have slightly different ways of doing things.
The design wind speed for Sydney (Category A at 41m/s) is the same as for Adelaide/south Australia.
In Sydney, we do not usually nail down the ridge capping.
Most roofers here prefer to use flexible pointing to secure the ridge capping down onto the tiles (and flexible pointing (used correctly) satisfies the ridge anchoring requirements for cyclonic winds up to c3 – 65m/s wind speed).
So, you may have a ‘storm in a teacup’ situation there?????
Hope this helps.
Jack
We have been told that 5 of our ridge caps need replacing – they are a rubber compound and when they become brittle the crows peck at them. Are these rubber compound ones readily available, or would we be better using something else? Thanks
Hi Jinny,
We do not have rubber compound ridge capping here in Sydney Australia and I have no advice to offer…
Jack
Thanks anyway, sorry to have bothered you.
Hi Jack,
I am in Melbourne and I am hoping that you are able to resolve some queries in my mind regarding bedding and re-pointing.
My house roof is hipped roofs in combination of gabled roofs. I recently got someone to re-bed and re-point the roof and his quote includes:
1. re-bed ridge caps in mortar mix
2. re-point all ridge cap and gable in flexible pointing with collars and weep holes
3. replace 6 valleys in colourbond valley irons
4. replace broken tiles
I looked at the roof after his work and I am not sure if he did the right thing. I would like to know your opinion:
1. He did not put mortar and flexipointing between the roof tiles and the new Colourbond valley irons. He said it is the dry finish for Colourbond valley irons. He said mortar and flexipointing on Colourbond will cause rusting and it will void the ColourBond warranty.
I am a bit worry that rain water will be able to get into the roof as I am in a windy area of Melbourne. What would be the right thing to do with Colourbond valley irons?
2. He did not do any work on the gable tiles. I can see the old mortar under the gable tiles are a bit loose. Again, he said the mortar and flexipointing will cause rusting to the fascia.
Based on his written quote, my understanding was that he would mortar and repoint the gable tiles. Is bedding and flexipointing the gable tiles necessary?
3. Can you explain to me the meaning of ‘repointing with collars’.
Thanks you in advance.
Connie
Hi Connie,
1. Your roofer is correct about the valley tiles. They should not be bedded to the valley. The wind should not be a problem.
2. It does not look like your roofer has quoted to re-bed the gables. Only a repoint. Normally, bedded gables have timber fascias – not colorbond.
Gables should be bedded on a metal ‘Z’ flashing/fibro strip. And then pointed.
3. Normally, a ‘collar’ is where adjacent ridge caps overlap. This overlap should be pointed.
Hope this helps/
Jack
Jack, can you please recommend a roofer in the Blue Mountains area.
Sam
Hi Sam,
Sorry.
I do not know of anyone in the Blue Mountains.
Jack
Hi Jack,
I’m currently researching what’s involved in rebedding all of the ridge capping on the roof of my newly purchased house. The roof is around 30 years old, has Monier elebanar concrete tiles and doesn’t look like it’s ever been repointed or rebedded in it’s life as quite a lot of the bedding is loose and starting to fall away, although it’s currently not leaking anywhere.
My question is, if I use a 2in1 bedding/pointing compound, where you just mix in a different amount of water depending on if you are bedding or pointing, will I have to go back over the fresh bedding and point? From what I can tell, the pointing on traditional mortar bedding is to adhere the ridge tile, but in my case I will be applying an adhesive bedding, so if I get the edge of the bedding neat enough (and the correct color) I can’t see any real point in pointing (pardon the pun), other than at the ridge tile overlaps.
Cheers,
Jon.
Hi Jon,
We have not tried the 2 in 1 bedding/pointing products that are starting to come onto the market.
From what I can piece together, these ‘new’ products mimic the old way of bedding and pointing…. The only difference is that the product is pre-mixed and contains additives that make it ‘stickier’ and more flexible.
In the ‘old days’ – roofers would mix their own bedding using their own sand/cement/lime/additives…
The ridge capping would be set into position on this bedding.
Then the roofers would come back with a similar mix (except it would have oxides to create a particular colour and more water to make it more ‘workable’) to point up the ridge capping.
…. with the new 2 in 1 product, it is the same process. The ‘bedding use’ of the product would be quite stiff and you would not be able to get a very smooth finish. Plus it would not be in the colour you prefer.
You will need to add oxide to the product if you want a particular colour (to match the ridge colour) and use this to do the pointing.
The reason for using slightly more water for this ‘pointing use’ of the product is to make it more workable and you can get a smooth finish.
The main thing that you must do is to provide weep holes at all the top ridges.
Hope this helps,
Jack
Hi Jack,
I have read the above, very helpful! Maybe you can help with some questions I have:
1. If I remove a single hip ridge cap carefully from the middle of the hip can I reuse it ?
2. I need to replace some terracotta tiles that are fretting and getting holes in them but I am having trouble finding replacements. My tiles are unglazed and about 257mm wide and 430mm long. I have found similar tiles that are 270mm wide but these don’t fit properly as replacements. Any advice on where to get tiles to match mine ? I have looked on ebay.
3. When I rebed a ridge cap should I use just a plain 3:1 sand:cement ratio or should I use some additives for best performance ?
4. I plan to use a pre-mix flexible pointing compound for repointing. I have seen on youtube people suggest that the ridge cap edges should be roughened a little with an angle grinder so the pointing can stick well, do you think this is a good idea ?
Hi Andrew,
1). If you don’t break the ridge, just knock off the old collar pointing and clean up the edges of the ridge and it will go right back in the hip.
2) The tile sizing is quite critical. Flip your roof tile over and there should be a name(s) stamped on the underside. Take a picture. If you are in Sydney, then contact Grant at Roof tile recyclers in Smithfield (02) 9756 3350. He will ask you for the name on the underside.
You can sometimes find roof tiles on ‘Gumtree’ for sale.
3) We use just plain 3:1 sand cement (often going to 4:1). No additives. The bedding does not need to be very hard or strong. It is the pointing that does all the work of holding the cap down to the tiles.
4) We have gotten sick of hand wire brushing the edges of the ridge caps and nowadays find it easier (and more effective) to use a diamond blade on a battery powered angle grinder to clean up the edges of the ridge capping prior to re=pointing.
Hope this helps.
Jack
Hi Jack.
How often would you come upon a job that needs every ridge cap rebedded?
A recent quote I got suggests a full rebed job as gap between cap a bed are over 3mm in places.
However I find most of the bedding in strong condition. I can remove caps off the bedging in alot of cases. But there is no crumbled bedding.
Question is if the bedding are structurally sound will repointing caps that can be removed but sufficient?
Seems like overkill to do everyone? Im guessing its to assist the warranty and guarantee of workmanship.
Hi Max,
We do not often rebed all the ridge caps on a re-point job. We often locally rebed ridges where the old bedding has fallen way or very loose. We will rebed the horizontal ridges if we need to weep hole them (old bedding has no weep ho;es).
The bedding is only meant to hold the ridge capping in place so that the pointing can be applied to bind the edge of the ridge cap to the top of the tiles. It does not matter if the bedding has cracks. Even new bedding will often crack as it dries.
It is the pointing that does the job of holding the ridge caps together and keep the water out… not the bedding.
Every now and then, I recommend a full re-bed if the roof has been repointed many times previously and it is too ‘fat’ under the ridges. It becomes too difficult to get the new pointing to bind the edges of the caps and have a neat finish.
If you want a very good looking re=point …. then it can only be achieved by a full rebed and point. This is why some roofers push for this.
If you want a re-point that works and looks quite good … then often there is no need for a full rebed.
Hope this helps.
Jack
Hi Jack,
You are a star sharing all this knowledge! Thank you!
While i’ve repaired, re-bedded our terracotta (late 1940s or so, Wunderlich) roof tiles about 30 years ago i had no idea as to how to do it but did it anyway. Used 1:5:1 cement/sand/lime. Did last well but needs fixing again (that’s why i’ve come to your site :)) and glad that i did. At least i can do it properly now.
Some decades ago i treated the tiles with 3 water :1 Phenol (disinfectant commonly used in the past). Soaked the lichen with it on a stinking hot day and by about 6 months later the tiles looked like new -all clean.
This time, since i installed a rainwater tank, i pressure cleaned them to remove most of the lichen and then sprayed household bleach on with a garden sprayer – hopefully that will work as well?
Best wishes,
Joe
Hi Joe,
I don’t know a lot about removing the lichen.
There is a product on the market called ‘wet and forget’. It will probably work better than your ‘home brew’.
Good luck.
Jack
Hi Jack
Movement over time on my concrete tiled roof has made the gap in the ridge widen and the capping is now not sufficiently wide enough to prevent leaks. How could this be remedied? Could a colour bond capping be used on a tiled roof? Or is there a method to seal with the existing capping.
Thx Trevor
Hi Trevor,
You will probably need to put in extra course of tiles at the ridge if the gap between the top row of tiles is too large.
You may be able to source wider caps also.
Jack
G’day, Jack.
Is pointing mortar always water-proof?
I had my C.1978 concrete tile roof re-pointed about 2 years ago as I had leaking problem which seemed to be coming in near the side of the roof where the tiles and brick veneer meet, and appears to be a very old leak. It still leaks. I haven’t got the tiler’s details. The mortar does not completely cover the fibro bedding at some points. The mortar seems to be absorbing the rain rather than shedding it. Should it be water-proof? I have had a builder advise me about installing some metal flashing to cover the pointing work. I know this is a bit vague. Comments? Thanks. Jim Ball.
Hi Jim,
Pointing does not have to be waterproof to function correctly.
The primary function of pointing is to protect the bedding under the ridge capping and bind the capping to the tile roof – to stop the ridges from moving and the wind maybe blowing them off.
It is not meant to waterproof the ridge capping – although it does help in shedding the rain water away. We have to make allowance for the pointing to lose adhesion to the ridge capping and crack (under excessive ridge movement). This will allow entry of water into the bedding.
Along the sloping hips, the seepage water travels down the bedding onto the downstream tiles and drains out – without causing any leaks.
Along the horizontal top ridges, the seepage water can not drain away. And that is why we need weep holes at the sides of these ridges.
If all of the above works, then the roof (not the individual ridge caps) will be water tight.
… On occasions, the roofer who laid the tiles on the sloping hips may have installed a tile that is cut too small under the capping. If this happens, then the trapped seepage cannot find an area of roof tile to shed the water downstream. Instead, the water drips into the ceiling cavity. Then you have a leak.
The solution is to remove the ridges to find the offending tile and to replace it with a correctly sized ‘cut tile’.
It is hard to bury your mistakes when water is involved.
Hope this helps.
Jack
Thankyou, Jack. It may well explain my situation. I have been able to locate the tiler who worked on the job and hope he can sort it. This is a great service of yours. I hope you get some compensation for your time.
Jim
Jack, just want to thank you for all the info & experience shared here.
I have only one question and it is in regards the weep holes. My roof (old Monier concrete tiles) does not have sarking, is there a reason in cases like mine to need the weep holes in the top ridge? I could see the logic behind it if there is sarking. not otherwise. Could you please clarify that?
Cheers, Mario
Hi Mario,
Appreciate your thanks.
Actually, it is the other way around.
If your roof is sarked up and over the apex of the ridge, then any leakage at the ridge capping (whether caused by lack of weep holes – or not) will drift down the sarking and hopefully into the gutter.
You will then have no leak onto your ceilings. And we will not even be aware that your ridge is leaking.
If there is no sarking, any leakage will drip onto the ceiling and you will know about it pretty quickly.
Therefore, it is more important to have weep holes if you have no sarking.
Jack
Hi Jack,
I am wondering how bad the bedding needs to be before replacing. I have a quote from a roofer and he says the bedding is fine, only a re-point is required. But when I get up there, I can see the bedding will easily pull away – it’s loose and essentially dislodged from the ridge on top and tile underneath. Can repoint in this situation still be ok?
Thanks a lot!
Mick
Hi Mick,
You can easily determine if bedding replacement is needed based on below:
The bedding under the ridge capping performs only two functions.
The first is to support the ridge capping so that ridges can be installed on a straight line just before pointing.
The second is to provide a foundation for pointing to be applied.
Therefore if new pointing can be applied over the existing bedding, then new bedding is not required.
Jack
Hi Jack,
My roof has been around for 35 years, and I have never pointed it. Now there are several places where the old beds on the ridges are loose and can be taken out by hand. The roofer told me to re-beding and re-point the roof. What do you think? How many years will the roof be re-beding and re-pointed?
Thank you very much.
Hi Yun,
Normal re-pointing cycles would be 15 to 20 years. The first re-point does not usually need re-bedding.
On the cycle after that, it becomes a bit more difficult to do just a repoint and removal and replacement of all the bedding (re-bedding) is usually recommended.
Your roof may be able to cope with just a re-point. Your roofer will have a better idea.
Jack
Hi Jack,
Thank you very much for your reply. I am sorry to have an appointment with a roofer without waiting for your reply. My roof is T-shaped. The cement between the two ridge caps and the roof tiles on the short roof has burst and loosened. You can take it out with your fingers. There is no cement burst or looseness on the long roof. The roofer came to check, he said that he had pulled the roof tile ridge cap is loose, and the entire roof ridge must be re bedding and pointing. 02/06 He only brought 6 pieces ridge caps of a different brand from mine. There is a 3 cm slot under the ridge cap, and the correct overlap between the ridge cap and the ridge cap is 3 cm. And he broke some ridge caps, so he only overlapped the ridge cap with the ridge cap by only 1 cm or 1.5 cm, and a few ridge caps were placed in the opposite direction. The original T-shaped roof junction has a slope shape on each side, allowing rainwater to flow into the gutter. Now roofer changes them to a vertical shape, and the rain rushes to the gutter.
May I ask you; is this kind of roof weak? Is there a problem with the quality? Do you think it needs to bedding and pointing again? Do you think the T-shaped roof joint should be modified?
Thank you very much.
Hi Yun,
I cannot comment until I can see some good photos of what was done.
Jack
Do you know of any good roof repairers in Wollongong?
Sorry,
We do not know of any good roofers in Wollongong.
Hi Jack,
I saw my neighbour’s roof ridge cap rebedding a couple of years ago and a metal tray (or flashing) was installed under the ridge tiles. Now, my house also need rebedding and repointing and I was wondering what purpose those metal trays under the ridge cap serve and whether it is a good idea to have them. I also need to know where can I get them and what are they called? A google search did not reveal much, quite likely because I may have used incorrect terms/names for them. Please point me to any further information about them if you know of any source.
Thanks
Hi Rawender,
Most of the traditional ridge capping have lap joints. The laps (called collars) are pointed and this waterproofs the ridge along its length.
No flashing is needed under these ridge caps.
Tile companies (like Monier A-line ridge) have released ridge capping that do not lap. In the name of form over function, there is a gap between the ends of each ridge cap to let water in!
This means that a waterproofing flashing is needed under the ridge capping to catch the leaks and try to drain it back out.
If this flashing is not installed correctly (impossible to check after the caps have been installed), there will be leaks.
Your neighbor probably was stuck with this new style ridge capping.
There is a good chance that you have the old style ridge capping and therefore you don’t need any flashing under the ridge capping.
Jack
Hi Jack,
We have just had our 30 year old Terracotta tile roof repointed with Flexi-shield mortar by a roofing contractor.
After only a few days we have noticed two hairline cracks in the pointing along the ridge caps, in two separate areas.
Why would this be happening already?
Also we noticed there were no weepholes evident in the repointing along the ridge caps. We asked the roofing contracter and he was adamant that weepholes are not needed with terracotta tiles as they naturally drain any trapped water away from the roof ridge line. He said weepholes are only required with cement tiles.
This seems to contradict everything I have read here and elsewhere regarding weepholes.
Your thoughts?
Hi Christina,
Hairline cracking on freshly pointed ridge capping can happen. When the roof tiles under the ridge capping are not solidly supported, temperature can cause movements and induce cracks.
That is why weep holes are needed. The purpose of weep holes is to cater for the future cracking of the pointing (causing seepage of water onto the upstream lip of the roof tiles under the ridge capping). Pointing will crack at some stage. It is impossible to avoid.
Most terracotta roof tiles have ridges on its upstream edge (concrete roof tiles don’t), and provided there is enough overlap by the ridge capping, seepage water will not overflow these ridges. Instead, it will drain into the side water course (which acts like a weep holes).
So, your roof contractor is right if there are full roof tiles under the (wide enough) ridge capping.
However, it is not always possible to have a full tile under the ridge capping (due to the dimensions of the roof). The tiles are laid from the gutter up to the ridge and the last row of tiles are often cut.
And when terracotta roof tiles are cut, they function the same as concrete tiles (NO upstream ridge to stop water from overflowing the edge). Therefore, weep holes are definitely required,
You will need to measure the last top row of tiles to determine if it has been cut… and therefore need weep holes.
Hope this helps.
Jack
Hi Jack,
Thanks so much for your excellent information.
Regarding cracks forming along the ridgeline pointing when the tiles under the ridge cap are not solidly supported… does this mean the bedding underneath has not been adequately prepared and smoothed back?
We are concerned that water may eventually enter through these cracks.
( Also Flexi – point is advertised as being a lot more fluid and flexible than standard mortar and much less likely to crack so we’re a little concerned to see these new cracks so soon . )
Regards
Christina
Hi Christina,
Concrete shrinks as it dries and is expected to crack. So, cracking is normal.
Flexipoint (and anything flexible) only has a limited range of flexibility. And when movement exceeds this amount, it will crack.
Jack
Thanks for your information, Jack.
Much appreciated.
Christina
Hi guys
Just wondering if ridge tile collars need to be pointed by code or not.
Cheers
Kev
Hi Kev,
The ‘code’ is silent on the finer details like pointing collars.
My view is that pointing collars increase the security of the ridge capping against slippage and wind uplift.
If the collars on the horizontal ridges are left un-pointed, it permits water seepage ‘behind’ the bedding and the importance of weep holes increases dramatically.
Un-pointed ridges on the hips are less prone to water seepage.
In summary, I (together with pointing manufacturers) recommend that all collars are pointed.
Jack
Hi,
What is the best premixed roof tile bedding mortar to use?
Or what is the best cement to sand ratio to use? If I do mix it my self can you recommend what type of cement and what type of sand.
Thankyou
Hi Tony,
My guys have tried the premix roof tile bedding mortar on the market … and they have not found one that they like.
They prefer the old style bedding – which is approximately 3.5 parts ‘yellow brickie sand’ and one part ordinary builders cement
Jack
Jack, great information via you videos, well done.
Question – We have a glazed roof tile and where the valley is there is no bedding/pointing under or on these tiles.
Do they need bedding in the valley?
Hi David,
I do not recommend bedding along the sides of valleys because it will introduce accelerated corrosion of the valleys,
It can also suck water into the bedding and drip the seepage over the edge of the valleys.
Hope this helps,
Jack
Jack,
This helps a lot, thanks for your valuable time.
Dave