Sealing a cracked asbestos roof sheet,

[plewlandsbob]

Hi guy
Can anyone recommend a suitable sealant, to seal a cracked roof sheet?
Recent strong winds must have blown something into it. Rest of roof is in good condition.
Thanks
Robert

 

[oldbikedavey]

Hi guy
Can anyone recommend a suitable sealant, to seal a cracked roof sheet?
Recent strong winds must have blown something into it. Rest of roof is in good condition.
Thanks
Robert

Cromapol is your friend, but slap it on good and thick......

 

[Onoff]

Clear CT1 for a quick fix.

 

[Gareth J]

Slip a valley of skylight in from underneath to transfer any dribbles onto the next sheet. Skylight is thin and flexible enough to wriggle into most situations.

No need to risk getting on the roof or disturbing the ACM.

If the hole is right near the top of a sheet, you can do the same from above. But I can't recommend getting onto any cement/asbestos fibre roof.

 

[Craig-SM]

I’ve got the same problem. Tried fixing it with a fibre reinforced repair paint but it just split again. The 3 inch profile sheets I have are impossible to get hold of now but you can get the steel ones so thinking of slipping one of those under it and screwing it down again.

 

[zzr1200]

Another possible solution, as long as access is fairly easy..... clean around crack/surface>prime>use wallpaper type roller to apply/seal,
width options available for various sheet profiles

Bostik Flashband Primer

• Ideal for cold, damp conditions• Fast drying, easy to apply• Solvent based• Use before applying Bostik FlashbandBostik Flashband Primer is a solvent-based bitumen primer. Apply to porous, rough, dusty or damp surfaces to improve adhesion prior to applying Bostik Flashband (code 97581), (code...

www.toolstation.com

Bostik Flashband

Whether it's for a new build or an emergency repair, using Bostik Flashband makes the job quick and easy. This self-adhesive bitumen strip bonds instantly to a wide variety of building materials, providing a permanent watertight seal.Flashband is a great choice for repairs to lead flashing...

www.toolstation.com

Bostik Flashband

Whether it's for a new build or an emergency repair, using Bostik Flashband makes the job quick and easy. This self-adhesive bitumen strip bonds instantly to a wide variety of building materials, providing a permanent watertight seal.Flashband is a great choice for repairs to lead flashing...

www.toolstation.com

Bostik Flashband

Whether it's for a new build or an emergency repair, using Bostik Flashband makes the job quick and easy. This self-adhesive bitumen strip bonds instantly to a wide variety of building materials, providing a permanent watertight seal.Flashband is a great choice for repairs to lead flashing...

www.toolstation.com

 

[Gareth J]

Flashband works ok. And I used to use it.

But you really need to wire brush the surface, while it's dry, from on the roof and heat it on. Asbestos and fall risks are too real for that

 

[zzr1200]

Flashband works ok. And I used to use it.

But you really need to wire brush the surface, while it's dry, from on the roof and heat it on. Asbestos and fall risks are too real for that

Crawl boards or a sheet of ply, but I'll agree repairing Asbestos roofing can be dodgy.....

 

[Onoff]

3D print a piece(s) of matching profile and stick on with.....CT1.

Whatever way you do it be careful if cleaning the old profile up ref any dust etc.

How long's the crack?

I've some of this aluminised, torch on roofing "felt".

https://flic.kr/p/2oofNc8

 

[Keith 66]

Wire brushing old asbesto is well dodgy. Last time i fixed one i just washed it off with a hose & broom, waited till it was dry & gunned a thick bead of Arbokol 1000 polysulphide along the open crack & beyond it inside & out. Flatted it with a wet finger. Ten years later it was still good.

 

[reb78]

I remember turning up to my grandparents one sunny day in the 90s. Grandad had removed the asbestos gutters and was sanding them and the asbestos soffit boards down ready to repaint. He did all this with a roll up hanging from his bottom lip. I went inside, had a cup of tea with my gran and left fairly quickly.

 

[Porkypine]

I've tried repairing cracks in asbo wiggly roofing many times, I've only had limited success as a very temporary fix with sealants. however I guess there are sealants out there that work as in @Keith 66 post

 

[minimutly]

Slip a valley of skylight in from underneath to transfer any dribbles onto the next sheet. Skylight is thin and flexible enough to wriggle into most situations.

No need to risk getting on the roof or disturbing the ACM.

If the hole is right near the top of a sheet, you can do the same from above. But I can't recommend getting onto any cement/asbestos fibre roof.

I like this solution. In the past I've cut some lead flashing, shaped it exactly to the sheet profile and used tigerseal to stick it down - permanent fix.

 

[minimutly]

Wire brushing old asbesto is well dodgy. Last time i fixed one i just washed it off with a hose & broom, waited till it was dry & gunned a thick bead of Arbokol 1000 polysulphide along the open crack & beyond it inside & out. Flatted it with a wet finger. Ten years later it was still good.

Friend of mine spent weeks with a B&D drill and wire brush cleaning the roof of their post office. He was around 15 I guess. He's still around full of health...

 

[plewlandsbob]

The crack is only about 4 inches long. Easily accessible from a ladder, as wall are only 8 feet high and crack is only about 6 inches in from bottom edge. Definitely will not be going onto roof. I think i have a bit of flashing kicking about . Will try sticking it on, with some CT1.

 

[plewlandsbob]

Storm Dave is just starting to arrive. Will be a job for another day.

 

[Melvyn Best]

I used brush on seam sealer on a crack in my workshop roof , ten years later it was still watertight

 

[addjunkie]

Clear sticks like Schit will fix it. Or a tube of leadmate.

 

[Dapph2]

Crawl boards or a sheet of ply, but I'll agree repairing Asbestos roofing can be dodgy.....

I used four sacks stuffed with straw under two full length scaffold boards to crawl from front to back of my garage roof.to effect a repair using a flexible paint on rubberised mastic that had fibre glass in it on the outside of the asbestos roof sheets .

 

[Keith 66]

A mate of mine oop north had a fire in his barn, Asbestos roof damaged. When it was fixed under insurance he went up there & walked off the crawl boards. He is a big lad 6'4" & heavy. Went through & fell 20 odd feet down onto the concrete. Busted leg, hip, pelvis, several vertebrae, ribs, arm elbow etc. Spent months in hospital recovering. Dont think he will ever be the same again.