Flat roof leak

patrickolee

Hi,

I'm having a problem with a leak. Think it's coming from the flashing on the flat roof extension. The base of the flashing is not secured to the flat roof... should it be? Also have a little moss and stuff under there. Anyone know what I should do? I've hopefully attached a few pics of the problem. Thanks

patrickolee

It's raining very hard out there :-(

*shivers*

tapest

patrickolee wrote:

Hi,

I'm having a problem with a leak. Think it's coming from the flashing on the flat roof extension. The base of the flashing is not secured to the flat roof... should it be? Also have a little moss and stuff under there. Anyone know what I should do? I've hopefully attached a few pics of the problem. Thanks

Hi P
That roof covering looks old...you could do worse than having it recovered. However, If that flashing is torch-on felt...then it's supposed to be torched on. If that was was High speed gas used ( hotter ). Another worry is what type of decking was used, if marine ply or shuttering board you're ok. But if the roof is that old the deck may be chipboard...All will need to be replaced as the chip swells and breaks etc
Remove flashing and replace. This will give you a chance to see whats underneath. Rootfiller timber (triangle shape) should be behind the flashing (for support).
If everything is as it should be, try somehow to clean up the felt you are going to flash to, probably quick blast of high speed torch...but not prolonged heat as this will buckle it. Reflash with plenty of overlap (everywhere).
Roof may be leaking away from flashing and running back under plashing, but flashing does look bad.
By the way the roof is the wrong colour...Paint it silver (special paint)
regards
t

patrickolee

Thanks for the reply tapest. Had another look last night, found a little hole under the flashing that looks like it might have been the root in for the water. Like you said, water flowing down the flashing and back under and through the hole. Had a little mushroom growing in it! The brother in law is going to give me a hand to tackle it at the weekend. He has blow tourch. Will get some silver paint too.

Thanks again

-patrick

rooferPete

Hi Patrick,

Good advice from tapest worth looking at a new roof because the covering looks like old type green mineral felt.

First image suggested flashband was used as the flashing, the last image suggests aluminium that was coated with a bitumen based sealer.

Take care trying to prime the roof using a torch, the old mineral felts can lift off the roof if overheated causing more trouble especially in hard frost.

An easy to try option would be a couple of tubes of Rubberoid All weather mastic (oil based), dry off the suspect area and apply a blob of the mastic from the tube, heat a clean scraper and work the mastic into the hole and the surrounding area.

Also apply the mastic to any visible cracks like in image 3, it looks like the flashing was sealed to the roof so you could run a bead of the mastic along the edge of the flashing.

Heating the scraper or trowel should allow you to work the mastic into the cracks without dragging it away from the surface, keep the flame away from the mastic as it is oil based and can catch fire.

Another product from the same family is Rito, both are cheap so not to be regarded as long term repairs but ok in an emergency.

Silicone would be a waste of time and money because it has nothing to bond to, take care, use good industrial type gloves a brick may be handy should you have to lie the torch down if doesn't have a stand.

Also as tapest said the roof deck may be chipboard so take care not to put your weight on any areas that may be soft or your foot might go through the roof.
.

tapest

Patrockolee
"And there skeaheth the expert" as the name implies. Any further info required or points clarified, he's your man....

Nice to hear you again, Wondered where you'd gotten to. FYI foundations being dug by hand. Had trouble with neighbour over Baby Skip Bags. ( me being helphul and paying more rathen than getting normal skips or hook skip to ease congestion). Gardaí and Council on to me. And I was entitled to use skips without licence. So there ya go, only a cod being too nice.
3am ..going to get some ZZZZZ, as soon as I finish my baíne and Milkchoc Goldgrain ( Nah Nah nana naahhh) (private joke patrick)
Regards
t
Something went wrong with "boards" ..wasn't able to post...had to leave pc on ...maybe it's that age thing again lol

patrickolee

Thanks guys. I attacked it today. Filled in the hole and put filled in the edge like you said Pete. Then I burnt a little felt over top. Looks waterproof now, fingers crossed. Thanks to both of you for your advice. Muchly appreciated.