Fixing a roof leak

[Arron]

Hi folks. I am worried about leaks in the roof. If you look at the attached photo, you can see that there is a sizeable gap where the last row of tiles lays over the flashing. Its OK on the left hand side, but on the right hand side I think it will leak when wind-driven rain comes in from the right direction. Unfortunately its not possible to bed down the tiles any better - the whole roof is a bit ramshackle. Is there some way to seal up the gap under the right-most 4 tiles - or at least reduce it. Thinking about silicon but can't really see how it would help.

The flashing is turned up correctly. The whole roof is flatter then it looks in the photo - hence my concern.

cheers
Arron

[Ian007]

Aaron,
how far up under the bottom tiles does the flashing sheet go?

It should extend up a couple of tiles if its a fairly flat roof.

other than that its lots of ugly silicone or make some cement sheet sutouts to fit and then silicone them in. but having said that i bet there is a product already available for this very job, its just that ive never seen it and im on a roof most days for work.

Cheers Ian

[juliussee]

Hi,



You can get a compressible bitumen foam type product which you can insert under the bottom edge of the tiles to stop blowback, that should help.

If the flashing goes back far enough under the tiles and has a turn up then I don't see how there will be a problem. What's all that silicone for? The Trimdek sheets should be turned up at the back so should not leak there.

Otherwise you could just stuff anything compressible to fill the gaps at the bottom edge of the tiles to stop blowback.

How far under the tile does the flashing go?


Regards

Adrian

[Ian007]

Hi,
You can get a compressible bitumen foam type product which you can insert under the bottom edge of the tiles to stop blowback, that should help.

can you get that stuff in that sort of profile or is it just in a staight roll??

Cheers Ian

[Arron]

Adrian, the silicone was put on by the roofer who layed the iron. He did a really lousy job (cost a lot, though) and wind-driven rain came through that joint and ruined the ceiling underneath. That was his attempt to fix it.

The flashing goes under the tiles for about 2/3 the length of one tile.

About this bitumen foam stuff, is it compatible with expansion/contraction and all that other mysterious stuff which happens on a roof ?

thanks
Arron

[Barry_White]

The bitumin impregnated foam is called Compraband. I dont think Compraband comes in profile but it does come in various thicknesses.

Lysaght sell profiled foam infil strips for the various roof profiles but isn't impregnated but is made from high density foam that wont allow water past.

You could use the compraband under the tiles and the profiled foam between the flashing and the roofing iron. They make the profile for both the top and the bottom of the roofing iron.

[Arron]

Thanks guys. Can anyone suggest where I can buy some Compraband. Googling gives no hits, and I assume its not the sort of stuff that comes from a hardware stored.

thanks
Arron

[Barry_White]

Arron

I'm sure I have seen it in Bunnings if not look for a good builders hardware store. You should be able to pick it up there. It may go by another name but Im sure a good builders hardware store should know it by the the name Compraband

[Arron]

I bought some BIYSEAL impregnated foam strip at Bunnings today.

thanks for the help
Arron

[ozwinner]

Ya could have used mortar also, like they used to use in the good ol' days..


Al

[Jacksin]

Looking at Aaron's pics, where someone has plastered silicone, I wonder if the leak is under the flashing because the iron is not 'weathered' at its end or the flashing does not cover the roofing iron far enough.
Jack

[Arron]

Jack, there was a leak from between the flashing and the iron - just as you suspect. That was what damaged the ceiling in the kitchen (did I mention that). The iron was not turned up at the end properly, and the gap between iron and flashing was too large as the flashing was not fixed down neatly. And this from a professional roofer !!!!!

This roofer was the second one to have a go. The first one was actually a builder, not a roofer. There had been a small leak for a long time, and he did a nice looking job but actually made it many times worse - so the next time it rained the water came bucketting in and ruined the ceiling in the sunroom.

Anyway, I think that leak is fixed now, and I am concentrating now on the gap between the flashing and the tiles, as a possible source of future leaks. The gap just seems too large to me.

Arron

[TassieKiwi]

Two things. Rain driven by wind presssure will travel alarming distances in a house (DAMHIK), like 300mm vertically:eek: so it would blow right up yer spout there. Second - do not rely on silicon alone for waterproffing - it wil lfail in time.

You could get the dude back to do it properly, install a longer piece of flashing over the too short one and/or use that 'space foam' stuff, or good ol mortar to block the holes. IFfyou can stop the movement of air then you're right.

[martrix]

Fcuk!

Just had a big storm in the Eltham area with serious rain. Haven't seen rain that heavy for a long time and it looks like its gearing up for another dump looking at the BOM radar.

Water got into the cupboard where I store my veneer stock . Got some Quilt maple and some burl .. Hopefully it doesn't stain it too bad, and looks like I will have a date with some glycerin and the vacuum press .

Note too self....fix the effing flashing and clean out the gutters.

[bricks]

IMO silicone should not be relied on to seal a roof.

Here's some links to what i believe are the best quality manuals on roofing for tiles and steel.
http://www.bluescopesteel.com.au/ind...F600C04FCF6B8F
http://www.hamiltonroofing.com.au/glossary.htm
http://www.harmonyrooftiles.com.au/m...oreword.html&0
http://www.tufftile.com.au/technical.html

Im not real good at internet related stuff so i cant navigate you to exactly what you want. You need to go to the sites and download the available pdf's. I finished downloading the bluescope lysaght manuals this arvo and its 954 pages on its own, but they have broken it down into sections, so you dont download it all.( you want section 11, flashing) there are diagrams and pictures aswell.

Id probably get the local authority to look at it if you can be bothered, that sounds like a poor job to me.

Because you say your roof is flat maybe run the flashing further under the tiles than recommended, flat roofs IMO are harder to seal because gravity doesnt help you as much.