Asbestos Corrugated garage roof leak

I have a double length detached garage built circa 1976. The roof is leaking through the joints in what I believe is asbestos cement corrugated roofing. Around the area of the joint water seeps through and I can see some of the roof is damp.

I really do not want to replace the roof, I intend to move within 5 years but would like to get it watertight or at at least as watertight as possible without spending too much.

I have looked at various tapes and sealants but don't really know what to go for, wonder if anyone can point me in the right direction please?

Thanks as always

Jim

The only sealant tape I have ever found to work well is bitumen backed flashing tape. It's a foil type tape with a thick coating of bitumen on the back, heat the bitumen up with a hot air gun or a small blowtorch and it will stick to practically anything. The instructions say it can be just pressed down with a roller but i've never found that to be effective, it needs the extra heat. Just think of it like a mini version of torch on roofing felt. It comes in 2" and 4" wide rolls (that I know off, maybe others). 10M roll of 2" is about £8 from B&Q.
If your roofing sheets are damp then dry them off with your blowtorch first.
Most importantly of all make sure you use a crawlboard to spread your weight as a cement sheet roof does not have much strength.

best of luck

cheers

Stewart

A tin of Acrypol or Flexacryl works well, just brush it on, it comes in grey and available from your local roofing merchant.

Oskool said:

A tin of Acrypol or Flexacryl works well, just brush it on, it comes in grey and available from your local roofing merchant.

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That's what I would recommend. And no need to dry off the roof, just brush it on. For added protection, flashband can be stuck into it

Thanks gents,

I'm off to the builders merchants tomorrow to get some although in this weather might have to wait a little while till it warms up...

What stuff did you use in the end??
I've got the same problem and currently have things under tarps in my garage.
Have found Flexacryl at Screwfix but it only comes in 1kg pots and my roof is 21sqm.
B&Q have Isoflex Liquid Rubber Black 2.1L.

Any recommendations anybody? The whole roof needs covering with whatever gunk I get cos there's that many weeping bits inside...

Cheers!

The joints shouldn't just leak, unless there are visible cracks or chipped edges, or wind is somehow blowing water under due to not enough overlap. Condensation can sometimes form on the underside of these types of roof, so bear than in mind too..

Flashband won't work cos the surface has to be clean, and you can't get a brush and start scrubbing the dirt and lichen off of asb sheets, too dangerous. The paint on stuff is the best bet, but is usually only for small leaks or patches.
Carrots , you are much better off replacing the roof or you will be spending a fortune on a temporary fix, if you can't afford to do it all, then do a bit at a time, use the sheets you do remove to overlay and patch up the rest of the roof you still haven't done.

The corrugated btumen sheets are best bet and only about £8 from wickes.

I used ISOFLEX which came as a thick black rubber type paint. My main problem was the joints between the corrugated joints where water was seeping under then running down the inside of the panel. I got away with painting the joints with an overlap of about 8 inches. It takes a bit of drying and can run if layered on to thick so I put on three coats over 3 days. Other than in the very heaviest rain I get no leakage at all and when it does come in it's no more than a drip. Previously I could watch it drip into buckets.

My roof covers a triple length garage, my neighbour had the same problem and paid over £1000 to have Grey Flexacryl over the whole roof. The tin was enormous and it took them two days of hard graft.

I did mine with the hope the paint would do the job but was always prepared to take the whole lot off and put up the Wickes sheeting which I just knew would be labour intensive and costly.

My advice would be to give the paint a go but be prepared to have to take the whole lot off.

Whatever you decide on be very carefull walking around on your roof. I use scaffolding planks which spread the weight but beware two neighbours with the same garages went straight through theirs!

Jim

If you give me an EMail add I'll send you some pics

i had the same type of roof, also leaked. 90 miles per hour winds soon fixed it and a 3 grand insurance quote!!

jpullen said:

I did mine with the hope the paint would do the job but was always prepared to take the whole lot off and put up the Wickes sheeting which I just knew would be labour intensive and costly.

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Yeah, the paints are a good idea and almost always a best option alongside a good old tube of all weather silicone.
But, I've never been a fan of asbestos roofing and you need to dispose of this stuff properly, not just dump it in the tip. =}