leak under kliplok roof flashing

Kliplok roofs often leak near the upstream ends

Many roofers in Sydney ignore the basic rules about flat metal roofs and as a result, we get to repair a lot of leaks in the Inner and outer west of Sydney – where a lot of kliplok roofs reside


Kliplok profile metal roofs are more expensive than the more common corrugated and “Trimdek” profile roofs. So why do we have to use Kliplok roofs?

When the roof design calls for maximum internal headroom restrained by roof height.

This calls for a roof as flat as possible and Kliplok can be used on roofs with a slope a low as one degree. But even though the manufacturer has done all they can to make the roof sheeting work on such a flat roof, it is still up to the installer to use the right techniques.

The basic rule that MUST be followed is to: Turn the upstream ends up and the downstream ends down.
Great care must be taken on the upstream end because this is the end that is more prone to water leaks. The most common problem is in the detailing of the upturn. A special upturn tool should be used and the upturn should be as high as possible. Otherwise water in very heavy rain will overflow the upturn and cause a leaking roof.

…And because the upstream end of the roof is usually covered by a tile or transition/apron flashing, the faulty upturn is hidden – making a roof repair more difficult.

So, instead of finding out exactly where the upturn problem is, many resort to sealing the kliplok flashing to the metal roof sheeting with silicone or some other sealant – and they think that they have done a smart roof repair. In theory, this may seem like an effective way to stop the water from entering the upstream end of the kliplok roof.

However, for this to work, the sealant work has to be 100% water tight to begin with, and must remain so for the life of the roof. This is an almost impossible task for the sealant applicator, and impossible for the poor silicone sealant which has to withstand weather and the odd pedestrian traffic putting stress on the joint.

To repair the leaking kliplok roof effectively, the covering roof flashing must be removed and the faulty upturns repaired adequately.

So a word of advice to those who think that just sealing the gaps around the roof flashings will fix that difficult to locate roof leak …

Don’t do it!

16 responses to “How to trace a leak at a Kliplok metal roof flashing.”

  1. John Gilcrist says:

    Exactly my problem!!! Plumber cleaned up and sealed flashing now it leaks worse!!

  2. ak says:

    our roof is klip lock and every year it leaks during monsoon is there any permanent solution.Also,is there any possibility of roof flying away if wind is strong.

  3. Jack Yuen says:

    Hi AK,

    A well designed and installed kliplok roof should not leak or blow away. Find a good local roofer to check your roof out.


  4. Kay says:

    Hi, are you able to recommend a good roofer in the Newcastle area?
    I have a pitched metal roof meeting a flat klip lok roof. I have water leaking down my bathroom wall where flat roof area is. Thank you.

  5. Jack Yuen says:

    Hi Kay,

    I do not know of anyone in Newcastle who I can recommend.


  6. John says:

    I have looked at your videos Jack and only wish you were here in Brisbane so I could get an expert repair on my tiled gable to 1 degree Klip-Lok area. Love your work.

  7. Robert says:

    I have new Klip Lok roof that leaks. Roof expert says it is because the roof end is not hard against inside wall of gutter edge. Klip Lok say most unlikely for water to run back underside of roof (edging turned down approx 20 degrees, slope about 3 degrees). Any thoughts anyone?

  8. Jack Yuen says:

    Hi Robert,
    A 3 degree kliplok roof should be easy to waterproof.
    If the downstream end is turned down – then there is no possibility of water running back along the underside.
    Only two other possibilities remain:
    1) The quality of the turn-ups.
    2) The quality of the flashings.

    Hope this helps.


  9. Saeed Rahimi says:

    is there a fix for when the kliplok is bent ?


    somehow pull it up?
    I am in melburne

  10. Jack Yuen says:

    Hi Saeed,
    There are two situations:
    1) The ‘kink’ on the rib is at the lap between two adjacent sheets. You can hook the back claw of a hammer under the outside ‘splayed’ edge of the overlapping sheet. Give it a hard yank starting from the end of the roof (at the gutter). This will free the sheet partially from the clip. Keep doing this as you work upstream and you will have the overlapping half of the kliplok sheet slightly free. You can do a little bit of panel beating to the kinked rib of the overlapping sheet and the adjacent underlapping rib. You won’t be able to get this ‘perfect’… When it is all done, lay the sheet down and put foot pressure on the ribs at the location of the clips to lock the sheet back in.

    2) The ‘kink’ on the rib is at the middle rib of the sheet. This is a bit more difficult to fix. And since there is no lap joint in the pool of water, I suggest leaving it as it is because it will not cause any leaks. It will only shorten the life of the roof – and your roof is starting to rust anyway….

    Hope this helps.


  11. Toby says:

    Hi, thanks for the video on over flashing!
    I have a double brick wall with the outer skin acting as a parapet. There is a 30mm gap at the end of the klip lok (metal roof ends before hitting the outer skin of brick). This is directly over the cavity. The overflashing is installed correctly (without silicone), but this means the cavity is essentially always open to draft. Are you aware of options to stop the flow of air coming through the over flashing?

    Thanks in advance

  12. Jack Yuen says:

    Hi Toby,

    Best to keep water and air apart.
    To stop the draft, it is probably best to remove the barge flashing (overflashing)… then install a capping or gap filler over the cavity (to stop the draft).
    Then re-install the overflashing.


  13. Toby says:

    Ok, thanks Jack. Should a decent roof plumber manage to reuse the capping and flashings? They’re currently in good condition. Appreciate the advice ?

  14. Jack Yuen says:

    Hi Toby,
    The flashings should be re-usable.


  15. JOHN KOVACS says:

    Hi Great video – I have 40yr old kliplok and a leak thru the rangehood flu which goes out over 2 channels – they used lead flashing to seal and probably since then alot of silicone – what do u recommend these days ?
    I tried wakaflex over the whole lot but i think ive got to remove the silicone first – Any ideas?

  16. Jack Yuen says:

    Hi John,
    The best way is to install a ‘tray flashing’ from the upstream flashing of the roof to the downstream of the flue. This will let you put a normal ‘dektite’ flashing around the flue easier.
    Don’t forget to install ‘upturns’ (you can use angles attached to the pans and sealed with silicone) on the two pans that are just downstream of the flue. This means that water will not travel backwards to the existing leaking joint between the flue and the kliplok roof.

    Best of luck.


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