flat roof

We are in the process of having a huge dormer built. The approved drawings the builder is working from says single layer membrane roof covering bonded to19mm plywood, also sides from 25mm plywood (exterior grade ply). The builder has used 11mm OSB3 board all over (also gaps all over between...

Hi My house was built in 1950, it has a single story extension with a flat concrete roof. The roof does not leak but has always had condensation on the inside through the winter due to not being insulated. Whilst renovating I have removed some plaster from the ceiling and found that some of...

Hi Guys, new to the forum and DIY in general. Note, I have no DIY experience at all, except for assembling home furniture. I had a garden building built in 2018, and now the flat felt roof has already failed and caused a massive leak inside the building. Large puddles form on the roof, and...

Hello all, I have a flat felt roof Garage, which is in the middle of a large block. There’s a substantial amount of water ponding on top in a bottom corner. (I cleared this today along with cleaning out the guttering) There’s no guttering at the rear where the ponding is, only at the front so...

Just noticed I have a leak from my flat roof right in the corner of the room. Need a temp method of repair to stem the ingress of water. Weather is foggy and damp, it's a north facing garden and I hear a asteroid is about to hit my location. Putting aside the asteroid disaster for a minute...

This is a section of my flat roof extension. The top rafters simply support a suspended ceiling below the original ceiling. The bottom ones are only approx. 500mm short and are placed inside the RSJ that supports the building and connected to the frame that supports the roof light, I cannot...

I have a simple question, to which I have been getting conflicting answers: Can I cut a section out of a flat roof joist to run through some ducting? Happy for it to be flat channel. The rafters are 170mm. I've seen some info but think it's about floor boards: I have seen enforcement...

Our Victorian property has a flat roof side extension for the kitchen. The kitchen ceiling is in part under the original property and in part under the flat roof. A long RSJ props up the original wall of the house. We are going to fit a ceiling extractor above a new kitchen island. The...

Hi, I will be framing my flat roof using 9 x 3 timbers.... what size/type of nails do i use to brin git all together (noggings/overlaps/framing etc) ? Thanks.

Hi Guys So I had my shed/garage roof replaced 3 months ago. The guys who did it were to put bluntly, cowboys, who mugged me off and did a half hearted job and are now nowhere to be seen. i have tried to chase them up, but no luck. messages ignored and numbers changed i presume. Anyway, i'm...

Hi, Starting to build a man cave in the garden tomorrow... Could you please help me verify joists of 47x220 C24 are ok for a span of 5.65m? As far as I've found, some tables say it's ok and some say it's not. I'm also doing 2 skylights of 90x120 and doubling up the joists around them, so I...

Hi, I am renovating a property that had been empty for a while and there was a leak going through a flat roof which has a terrace on it, into the kitchen of the ground below. The leak has been fixed and the damaged plasterboard for the ceiling of the kitchen have been removed. At the moment...

First of all thanks everyone for helping with my self build, so much appreciated. Next stage complete the parapet wall design,roof timbers on for warm roof.My plan is to complete the top of the parapet wall either side,them fix the roof down. Need to keep the parapet wall to minimum height...

Morning all Currently building single storey extension warm roof construction.All walls up currently have all materials onsite for roof,need to get water tight asap.. I have taken plasterboard away to reveal joist and drilled through wall has a gauge,temporary inserted steel rods for 195...

Hi, I have been given GRP roof quote back in July. I have contacted the guy again and he said the insulation price has recently gone up by 20%! so I have to charge you more on insulation. Is this normal? Thanks

About a year ago I replaced my garage roof with a new flat roof. As far as I know I used the correct timbers for the 3.6m unsupported span - 45x175mm on 400mm centres with 1 row of noggins. The static load is about 0.25kn per sqm. I’ve just finished plaster boarding and noticed a pronounced bow...

Hi there! I am about to replace the flat roof above a bay window, removing the felt as it is starting to leak/deteriorate, and replacing it with a GRP one. I have a few questions and don’t know whether anyone can help?! I have attached a few photos of the existing roof. 1) The roof has a...

Hi, I am currently renewing a large cold roof which has rotted from the inside, no ventilation or vapour barrier with a GRP top. The roof is on a dormer where the roof joists joined directly onto to the ridge beam with no ventilation and no scope to convert to warm roof due to ridge height. The...

I had a new lean-to garage built two and a half years ago. It seemed to be a good job and I was very happy with it. (Only minor glitch I was aware of was that the roof has always ponded at the back, which is visible on the photo below but not related to the main problem). However, earlier...

Hi, a friend has recently used and recommend a paint on liquid rubber roof membrane called mono bullet roof. It sounds too good to be true as the application of it is very easy making it ideal for any DIY’er, simply roll the product on to a new ply deck. Also will save a lot in money. I plan...