leaking roof

[carol]

One the houses near ours has had foam installed up in to the spaces of the roof tiles to seal and waterproof it.. Has anyone had any dealings with this, is it any good?.. Can you recommend this or something else to make the roof better..We have the common tiles used...

[splitlid]

hi carol,
the only real way to fix a leaking roof is at the source.spray foam will not repair you roof,it will only divert the problem and maybe cause more issues.

[PeteC]

If it's the type of foam that's sprayed on as advertised in many RE magazines here, I've heard it is really a hard job to do once the house is built, especially for a two story house.

We have the silver sheet insulation on the inside of the roof and when there is a leak, that even makes it hard to find as the drops run down under the insulation sheeting and come out in a totally different location.

Luckily the workers with the development have become wise as to where the majority of houses are having problems and they've been correct so far in locating isolated leaks.

We seem to have a problem after a medium to high wind storm blows through, then it rains. Seems some gusts actually move some tiles very little, but enough to dislodge a tile to a small degree.

I'm afraid it's an ongoing problem as have been in 15 year old rental houses that still had occasional problems and those tiles had been bonded when installed but still leaked. Pete

[johnnyk]

I continue to believe that leaks are best fixed from outside. Anything else just diverts them.

[PeteC]

An update on this. Written by an HH company who specializes in the spray foam type roof insulation, but it makes sense apart from any marketing angle.

The article indicates that most houses here have steel roof beams. This is correct for houses built in the last 20 years or so. They say that on a daily basis the sun heats the roof and the steel beams expand. In the evening it cools down and they contract. This constant movement moves the roof tiles enough to cause very small misalignment over time, thus causing some water leaks when it rains.

Sounds logical. Pete

[chopsticks]

Will a few mm expansion and contraction matter too much as the tiles have a generous overlap ?
Also, won't the spray foam similarly split open due to heat expansion or does it retain some flexibility ?

[PeteC]

Will a few mm expansion and contraction matter too much as the tiles have a generous overlap ?
Also, won't the spray foam similarly split open due to heat expansion or does it retain some flexibility ?

No idea about the property's of the foam CS. Just thought the explanation about the expansion/contraction was plausible. Pete

[migrant]

Will a few mm expansion and contraction matter too much as the tiles have a generous overlap ?
Also, won't the spray foam similarly split open due to heat expansion or does it retain some flexibility ?

I've used a product over here in the states, and it does retain some flexability. I don't remember the stated allowances, but roofing was one of the suggested uses.

[PeteC]

OK, it's light here now and I went out and looked at the tiles on the sala, which are laid exactly like the tiles on the house roof. See below photo.

Every tile has the joint seam on the upper curved face of the tile. You can see the line and joint. I imagine this can indeed move/open slightly over time with beam expansion and contraction. Also, if there is some kind of chip in the underlying tile joint ridges caused when installing or shipping, this is where and how the water will get in IMO.

Don't use the photo as a good example of a house roof though. That sala moves slightly by itself in high winds and/or when a workman is up on it doing something. This probably moves the tiles around more than on a normal roof, which is why the seam lines may look wider than usual. Pete



PS: We all know hindsight is 20-20. If they would run a bead of sealant along the underlying tile joint line as they were laying each tile, it would probably prevent any problems for many years.

[Nereus]

Pete, the joint line you point out is laid over the solid centre part of the underlying tile. Water will not be able to penetrate into the roof space via there. The tiles have to move slightly; if you were to hold them in place with anything it would lead to cracking, probably just where the water could get in. One of the worst things that you can do with roof tiles is walk around on them.

I have not used the spray on insulation, but I believe it is flexible enough to allow for normal heat expansion.

[Super Joe]

Pete, the joint line you point out is laid over the solid centre part of the underlying tile

This pic gives you clear view of that and also the amount of overlap. Don't like the look of the steelwork, this is NOT one of mine.

Usually a decent roofer here will be able to spot areas where leaks are occuring, even if the location isn't obvious by water marks on the ceiling. If on the laid tiles there may be a crack or they've become displaced by something like wind or an ostrich landing on it, and if on ridge or any bedded tiles he can usually see gaps in the mortar and fill it with some of my wife's make-up.



SJ

[PeteC]

OK, thanks guys, scratch my theory. Next time we have a leak I'm going to go up in the attic with the guy and try to take a pic of the problem. Stay tuned, heavy rains should be coming Sept. and Oct. However, I/we are hindered by the aluminum foil insulation sheets up there. I'm positive any water runs along them and hits the interior ceiling far away from the source. Pete

[migrant]

I'm positive any water runs along them and hits the interior ceiling far away from the source. Pete

A friend had one of the biggest roofing companies here in California, putting in 70+ per week during the construction boom.

He also did service work.

I remember riding with him a few times when he went on the road checking his supervisors, etc.

What you mention Pete is oft times the case, but a good, experienced roofer can track it, or identify it, from a basic investigation.

[hhfarang]

What you mention Pete is oft times the case, but a good, experienced roofer can track it, or identify it, from a basic investigation.

That's the problem you'll find when you move to Hua Hin Migrant... there aren't too many of those at anything...