flat roof

  1. D

    Flat roof - felted with gravel (Internal leak)

    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...
  2. DerMitchie

    Moving rafters in existing flat roof

    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...
  3. DerMitchie

    Flat channel ducting through flat roof joist

    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...
  4. DerMitchie

    Flat roof joists in the way for ducting to pass through

    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...
  5. SS-ProjectBuild

    Correct nails for Timbers

    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.
  6. L

    "New" fibreglass shed flat roof already leaking within 3 months

    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...
  7. Y

    Joists for 5.65m span

    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...
  8. mjl215

    Correct Insulation for Flat Roof

    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...
  9. G

    Parapet wall

    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...
  10. G


    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...
  11. R

    Flat roof quote

    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
  12. C

    How much unevenness is acceptable in ceiling joists?

    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...
  13. D

    Flat Roof Drainage And Slope

    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...
  14. J

    Flat Roof Cross Ventilation

    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...
  15. D

    Flashing on fibreglass roof on new garage failed in 2 years

    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...
  16. B

    Paint on Liquid rubber roof membrane called ‘mono bullet roof’

    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...
  17. R

    New pitched roof (replacing existing flat roof)

    Hi, I am in process of replacing my existing flat roof with new pitched roof. After much thought, apex type pitched roof will be best option for this kind of structure. It is for kitchen extension at the back of the property. Photo attached. Following are the measurements: Length (from the...
  18. R

    Mono pitched roof ... possible

    Hi, I got a kitchen extension which is 5 meter long and currently has flat roof (which I am sick and tired of it as its leaking all the time + it looks ugly). So I was thinking about replacing it with mono pitched roof but I am not sure given the meaurement if its possible. Length of the...
  19. giznorm

    Another Garden Room - big ambitions and humble beginnings

    Hi all, After years of hanging around this site, I finally have a big enough project of my own to share. I am building a garden room (yes... it's another garden room post) with a view to discovering if I can learn enough skills to eventually build my own timber frame house extension (which I...
  20. A

    Would 2 x 8" x 4" Steel beams / Rsj's be engough for a 6.5m garage roof ?

    Hi, Just after some thoughts on Rsj sizes for a flat garage roof Garage is new built single skin 6.5m x 6.5m and its got 2 pillars on the left wall and 2 pillars on the right wall evenly spaced out @ 1/3rd & 2/3rds of the way, So will need 2 Rsj's to support 6"x2" joists (400 centers) with 18mm...