Temporary repair to flat roof

[bernardgreen]

The kitchen extension roof in question is part over hung by the thatched roof of the main building a stone cottage. The thatch is less than a foot above the flat roof so no hot work is permissable on the flat roof.

The extension is single brick walls, the roof timber planks across joists. Seems to be a single layer of blueish grey felt. From the under side it is obvious that pitch has been used to glue the felt down as it has run through gaps and knot holes onto the joists.

A disused brick chimney comes through the flat roof and one face of the brick work below the roof is saturated. It would appear that the felt to chimney seal has failed on that face or there is a hole in the felt ( non obvious ) close to the chimney. No apparent flashing on the chimney.

Replacement of the thatch is planned for 2013 or there abouts when the flat roof will be fully accessible and a new roof with insulation will be fitted.

One suggestion ( from a non roofer ) was to use a cold curing or two part resin in the area around the chimney as a temporary seal. This would seem to be a way to get a temporary seal but is there a better way ?.

 

[catlad]

acropol is a thick waterproof sealer about £ 50 for 5ltr that should do it

 

[Space cat]

When I had a leaky flat roof, I got a lot of valuable advice here:

//www.diynot.com/forums/viewtopic.php?p=1675738#1675738

I used primer and self-adhesive flashing strip and it's still watertight.

 

[bernardgreen]

Thanks for the advice. I have spoken to Acrypol and then to a local stockist and it looks like that will be the answer.

Also looking into the planning situation about removing the chimney as it serves no purpose now and is not part of the listed building.

Use of even a hot air gun on the roof is banned due to the close proximity of the thatch so it will have to gone on wet bricks.

 

[Space cat]

Use of even a hot air gun on the roof is banned due to the close proximity of the thatch

Keep it on a low heat. You could even use a hair dryer; it'll just take longer. I've found that bitumen will soften and become sticky at body temperature. I've used odd scraps to fill small holes, warming it with the hot air gun then moulding it into place with my fingers.

 

[bernardgreen]

Even hot air guns used on the roof would invalidate the insurance.

 

[Nige F]

remove the chimney - seal round the ouside of the stub with acrypol - make a wood flat roof over the chimney stub and cover with a bit of shed felt

 

[bernardgreen]

Removal of the chimney is an option for when the roof is replaced in a couple of years time when the thatched roof is being replaced.

 

[bernardgreen]

Having applied a tin full of Acrypol onto the roof and cracks in the parapet wall and chimney it seems the leak(s) have been closed. It seems to have survived two heavy downpours without any more water coming through.

Thanks for the advice.