[this is my first post here, so i apologise if i'm asking things that have been answered before elsewhere, but i have had a look, and my problem seems to combine lots of issues]
So... I am currently trying to repair a flat roof over my garage at home as the current surface is blistered and leaking. One big issue with the current roof (to give some context to my plan) is that there is only one internal drain point on the roof, and as the roof is surrounded by parapet walls and does not have a sufficient gradient for water to run off to the drain, it ponds and puddles.
My original plan was to completely remove the old surface, insert firrings on the joists to create a gradient and lay new OSB boards and an EPDM membrane.
What i hadn't realised was that the current roof is made of a thick layer of tar, with a chicken wire-type mesh running through the middle of it - and despite efforts with various pick's, pry's, scrapers and chisels, it is extremely difficult to get up.
So what i have now is a severely pock-holed tar roof, where i have tried to take up the surface, starting by punching through the blisters.
my revised plan is to fill the holes to try to make a reasonable flat surface, then lay firrings/OSB/EPDM on top of this to create a new (hopefully sound) surface.
My questions and worries are:
- Do I need to use tar to fill the holes, or is there anything else that would be suitable?
- what can i do to prevent more air blisters forming? (as if i'm building a structure on top of a surface that s likely to develop new air pockets, i'm sure some terrible things would happen)
- Is it even necessary to use EPDM or is there a way i can repair a tar roof with an improved water run-off scheme? (i have already bought the OSB boards and EPDM, however if it would be better not to use these i could always sell them on.. or something)
The only other thing to consider is that the roof is used as a balcony, and has doors that open onto it, so any solution needs to be structurally capable of holding people.
If you've managed to read this far, then thank you very much, and if you have any tips or advice... then there'll be even more thanks!
cheers,
alex
So... I am currently trying to repair a flat roof over my garage at home as the current surface is blistered and leaking. One big issue with the current roof (to give some context to my plan) is that there is only one internal drain point on the roof, and as the roof is surrounded by parapet walls and does not have a sufficient gradient for water to run off to the drain, it ponds and puddles.
My original plan was to completely remove the old surface, insert firrings on the joists to create a gradient and lay new OSB boards and an EPDM membrane.
What i hadn't realised was that the current roof is made of a thick layer of tar, with a chicken wire-type mesh running through the middle of it - and despite efforts with various pick's, pry's, scrapers and chisels, it is extremely difficult to get up.
So what i have now is a severely pock-holed tar roof, where i have tried to take up the surface, starting by punching through the blisters.
my revised plan is to fill the holes to try to make a reasonable flat surface, then lay firrings/OSB/EPDM on top of this to create a new (hopefully sound) surface.
My questions and worries are:
- Do I need to use tar to fill the holes, or is there anything else that would be suitable?
- what can i do to prevent more air blisters forming? (as if i'm building a structure on top of a surface that s likely to develop new air pockets, i'm sure some terrible things would happen)
- Is it even necessary to use EPDM or is there a way i can repair a tar roof with an improved water run-off scheme? (i have already bought the OSB boards and EPDM, however if it would be better not to use these i could always sell them on.. or something)
The only other thing to consider is that the roof is used as a balcony, and has doors that open onto it, so any solution needs to be structurally capable of holding people.
If you've managed to read this far, then thank you very much, and if you have any tips or advice... then there'll be even more thanks!
cheers,
alex
