Advice needed - flat roof

[yeti]

I have a flat roof on my workshop, and since felting it some months ago, the felt has lifted and crinkled in places and is holding water in said crinkles which is now finding it's way through the joints and into the workshop,

I've just been up on the roof and tried to pour felt goop onto the joints to try and slow it down, but the whole roof looks really crinkled now. I laid this in the summer when it was warm, and if anything would have expected the felt to shrink and contract as it got colder, but it seems the revers is true and as a result it's folding and crinkling.

Short of taking it all off and starting again, anyone got a quick and relatively cheap method of repair?

Had thought about trying to find someone with a tar boiler and simply pouring tar along all the joints, but for one, I don't know anyone with a tar boiler, and my local hire shop don't hire them.

Anyone care to offer some much needed advice before my new baby gets soggy......... :(

[bike mad]

yes,how many layers did you put down, if you did the job well it should be 3, and the first one should be heated up to the point that it melts, and thats the trick, you need a high power heat gun, and you melt the felt,
hope this helps:flame::burn::burn:

[yeti]

Originally posted by bike mad
yes,how many layers did you put down, if you did the job well it should be 3, and the first one should be heated up to the point that it melts, and thats the trick, you need a high power heat gun, and you melt the felt,
hope this helps:flame::burn::burn:

Helps in as much as I done it wrong in the first place! :(:(:(

[bike mad]

sorry to hear that. but a lot of heat spread round will melt the felt and you will lose the wrinkles with out breaking the felt'
:flame::burn::burn:

[guest1]

Shouldn't they also be cross weaved?

[phoenix n max]

Got one here too. I purchased the more expensive self adhesive layer stuff that didn't require heating and stuck it straight onto new exterior ply roof. The there was a top layer with the gritty stuff on that was also self adhesive and stuck that on top.
It's been 3 years and the roof is as perfect as the day it went down.

[yeti]

Originally posted by phoenix n max
I purchased the more expensive self adhesive layer stuff that didn't require heating and stuck it straight onto new exterior ply roof.

That was what I bought, but it obviously hasn't stuck despite me gluing all the joints. B*****D :mad:

[guest1]

Get a couple of bottle jacks and jackals.
Knock a few bricks out of one end of the garage and stick the jackals in.
Knock a few more bricks out then stick the bottle jacks in and lift the whole of the roof at one end so you get a 17 degree slope.
Problem solved.

[bike mad]

when you do the last layer the joints should go against the slope,
but the important bit is to get a good seal on the joints, it's done by melting the edge of the felt, ps when I say melt whot I mean is you put heat on it till it goes soft and the surface starts to run, I have found that you need a lot of heat as its a large area and the felt cools down fast, take my advice and hire a large gas powered heat gun, and keep it on the move as it will burn the out side of the felt and not have time to soften the center, :flame::burn:

[yeti]

Originally posted by bike mad
when you do the last layer the joints should go against the slope,
but the important bit is to get a good seal on the joints, it's done by melting the edge of the felt, ps when I say melt whot I mean is you put heat on it till it goes soft and the surface starts to run, I have found that you need a lot of heat as its a large area and the felt cools down fast, take my advice and hire a large gas powered heat gun, and keep it on the move as it will burn the out side of the felt and not have time to soften the center, :flame::burn:

Guess what I'll be doing this weekend................:mad:

Didn't really want to play with my new toy :mad::flame::mad::flame:

[phoenix n max]

I didn't have the heat stuff with mine- just bought some paint on tar type adhesive that was recommended to seal the edges.
The roof is approx 16 x 8 feet or so but like already said re the slope - it does have a very small slope on it so I suspect that helps. It had an asbestos roof on orignally that had gone porous - yuk!

I used this Ruberoid stuff http://www.ruberoid.co.uk/index.php?page=49 Cold Self Adhesive stuff.

Not much help if you gotta do it again though - sorry.

I did try some of that paint on stuff on the asbestos thats supposed to stop leaks but it didn't work for me no matter how thick I painted it on.

Tarpaulin til summer ?

[TopiToo]

Hello

phoenix n max, I have found the same problem with one panel of asbestos on my roof. (starting to go porous) will be getting some of the above recommended this weekend.

just out of intrest does the adhesive take to cold/damp asbestos?

Did you heat the felt or just paint it with tar?

regards

TopiToo

[phoenix n max]

Topi - not sure if it would stick to damp wet asbestos to be honest. Maybe Bike Mad can answer that one ? Is it corrugated asbestos ? I found mine was porous in the channel.

No the stuff I used didn't need heating but then it was done in summer and it was warm I recall.

The felt I used comes as a 2 part system. One layer is black, sticky and you layer that one way as already said - then the top layer sticks to the top in the opposite direction with the seams away from the rainfall so to speak - does that make sense ?? - anyway I also purchased some adhesive that was supplemental but I do like a bit of overkill, just to be sure.

We removed the asbestos first though and replaced it with ext ply before putting the felt on. I guess you could try sticking the felt direct to the offending asbestos, with a bit of luck it may just work for a couple of months to see you though til spring ?

[Jon]

What Yeti is not saying, is how big his roof is:o If you have built it to the size you where talking. Its to big in my eye for a felt roof. You might have been better off with a pre coated corrugated steel sheet.

Have a look here http://www.slecladding.co.uk/plastisol.htm

[yeti]

Originally posted by Jon
What Yeti is not saying, is how big his roof is:o If you have built it to the size you where talking. Its to big in my eye for a felt roof. You might have been better off with a pre coated corrugated steel sheet.

Have a look here http://www.slecladding.co.uk/plastisol.htm

It always was gonna be a bit iffy whether the felt was enough, but to be fair what is happening with the felt crinkling would have happened no matter what size. Ultimately I was gonna have a GRP coating applied, just looks like sooner rather than later.

[phoenix n max]

^ job done - wish i'd seen that before.

[PDL]

Buy a pointy roof. :cool:

[rcgbob44]

I had a flat roof over my garage bedroom that always gave problems so I had a hip roof fitted.........................now no problems at all, but it was expensive!