cs21

1:40 for a 5.m run im getting just over 5 inches.

YEs i will have that in mind to dress it down and even over the cavity for extra protection. My firrings i can purchase is 4.8m long and 95mm on one end tappered to 0 although they are hard got these days. I will have to make my own up either with a table saw, circular saw or even a track saw if i can get my hands on one.

I will be installing warm roof very soon with 150mm tissue faced insulation in 2 layers with an EPDM covering in one cover, 100mm and 50mm insulation staggered joints and will be mechanically fixing them with raw plug plastic thermal caps. There will be 18mm osb 8x4 sheets ontop of 9x2 joists built into the walls for a parapet. My question is would i get away with 12mm expansion gap all around the base of the parapet where the OSB meets the parapet wal and filled with expanding foam l or should i go with a wider width. Any internal work with T&G OSB i always install with a 12mm gap where this meets the wall, would a similar gap be ok in a warm roof. There will be ulutrix 600 vapor barrier installed on the OSB but will it bond to the expanding foam with the primer.

This is a grey area after my own research. 1:40 is ideal however 1:60 or 1:80 is fine. If solids in a sewer pipe can get away at 1:80 min then rain water can surely get away with 1:80 and no need to go as deep as 1:40.

Would this be similar to alutrix? SuperFOIL SFTV is the ultimate all-round building membrane for roofs, walls and floors. Water & vapour proof SFTV is also a foil radiant barrier that will reduce solar gain in summer and improve insulation in winter. SFTV's reflective properties add to the overall uValue of the building fabric. To achieve the maximum energy performance in new build and retrofit projects, SFTV makes an ideal 'airtight' layer suitable for the entire building envelope. Technical Layers : 3 - polypropylene reinforced heavy laminated foil. Width : 1.5m. Length : 50m. Coverage : 75m2. Colour : Silver. Weight per roll : 10.7kg. Thermal insulation values including 2x air gaps Roof : 0.95 R. Wall : 1.42 R. Floor : 2.8 R. Features Waterproof. Vapour proof. Air tight. Radiant barrier. Helps to prevent mold & damp. Enchances thermal resistance. Product Documents Brochure Data Sheet Range Brochure Specifications Dimensions Width1500mmLength50m Details PermeabilityVapour Barrier Air TightRoll Size75m2

YEs, the vaulted ceiling is already in place. This house was built 20 years ago and is finished. In this room there is a vaulted ceiling where im wanting to make another floor. From the floor to the peak, its 4.8 high. The rooom is 4x4 square and the slope of the rafters meets the wall plate at 3.1m of the flooring. Im wanting to install the new flooring at 2.4m high from the floor in this room. Install 9x2 joists, osb flooring and whatever flooring on top of this. Where i will be installing the joist runners, there will be a few block above this before the wall plate is and as i mentioned above, i intend to install the joist runners every .400mm with either M16 chemical fixings or Ancor bolts or both then joist hangers nailed onto this with the correct fixings. I do very much understand your concern and i do understand floors can collapse under heavy loads but if these runners are installed as i mention, i cant see the life of me how they would fail if its just normal bedroom loading. Is it not how these runners are installed. I could put Rsj's under the joists but this is over kill IMO.

I do appreciate your concern and advice and i do understand what your saying however, in a 4x4 roof with a maybe 600mm high above the joists in block and the roof load, i cant see where there would be any issues if i have 2 joists runners of 9x2 bolted into the wall with chemical fixings with m16 threaded bar or even m16 raw ancor bolts spaced at 400mm apart with joists of 400mm on joist hangers ever failing if its only loaded out on top with bedroom furniture , osb T&G flooring with either carpet or laminate on top.

No structural engineer for this job. Its in my own home and im very confident in doing this to regs and safely

Underground work is difficult to get exact! You never know whats under there. You havent said where you are. Prices range all over.

Then why is it firrings are cut with this slope.They are actually 95mm on one end and tapered to 0mm in the 4.8m lengths. It isnt far off the 1:40 and for a flat roof, i think thats efficient. Even 1:80 should let the water flow off the flat roof ok.

How does parapets leak heat! If done correctly they shouldnt let water in. Surely if the EPDM is laid correctly there will be no breaks in it to let water in. I could go with an overhang but what bothers me is one will be able to see the slope with the firrings. if the width of the roof is 5.8m and the firrings are 4.8 with 100mm taper, and with the extra taper for the other 1m needed, this will be noticeable. That is unless i run a 4inch length of timber where the last firring strip is needed to create a sq look rather than the slope. This will create a 4inch drop thou to one side of the fascia board.

I had planned on using the cheaper version of vapor barrier. What benefits would the more expensive version have. I thought even thou there is cheaper brands, they should still do. My method of a warm roof is 18mm OSB, vapor barrier, insulation at 150mm, 11mm OSB all screwed through with large screws with plastic caps then the EPDM on top. If i go with the parapet, i was going to use 2 outlets. What i had in mind was set the back wall, wall plate level, then the facing wall plate set this level with the back but have the furthest side of this wall plate slightly lower. This way when i put the firrings and the rain falls to the lowest point and stops at the parapet, it will also have a slight fall to one side so there will never be any sitting water pooling on the roof. Have never used the tapered insulation. Is it much more expensive!

I will be installing a new floor in a room with a vaulted ceiling to create 2 rooms with a new staircase for access to the first floor. What i intended to do is secure the joist runners on both sides of the room with either rawplug resin chemical threaded fixings or M16 Ancor bolts every 400mm spacing. The joists will also be 400mm spacing hung from joist hangers. I have been advised that m12 will be sufficient enough for this as there wont be much of a load above the floor apart from bedroom furniture and max two or three people at a time. Is there any particular joist hangers i need for first floor loads or would the strength of these hangers all be similar in the load capacities they can hold! I have also been advised by others that ancor bolts can cracks blocks if tightened to much. This would be a major concern of mine if they where to fail. Resin fixings sem to hold up well but its the waiting time and fiddling about getting them exactly into place for the joist runners to sit level that concerns me with this. Ill be using a 9x2 c16 for the joist and will be getting bolted into a 4inch thick block wall. What length of bolts or threaded fitting should i use. Would 110mm be sufficent. 50mm into the wall, 44mm for the timber and and 16mm for the bolt and washer

Hello, long time lurker first time post. Small scale builder and ill be building a small flat roof extension soon for a client soon. The extension will be 8m long, 5.8m wide and the clients have gave me the option of a fascia soffit overhang or a parapet for them for the roof. The roof will be a warm roof and will be covered with EPDM. They much prefer the look of the parapet or maybe a 3 sided parapet with one side opened to a gutter. Myself and the tradesmen i work with all have some experience with overhang flat roofs but none yet with a parapet. Would anyone from this forum have a parapet detail for capping it off with either a coping stone, concrete coping or other. My first thought would be aluminium coping would be the better option. The cavity will be full fill insulation at 150mm wide and closing it off with an insulated cavity closer on top. I would like to know the detail above this and below the coping to help keep damp away from entering the inner skin of block. If the parapet isnt to high of the roof, what i had on mind was i can fold the EPDM into the corners of the and up the parapet. The aluminium coping can overhang this, however with my limited knowledge of the parapet, would there be any other detail i would need to do for better water/damp proofing. Maybe i could run the EPDM up and over the cavity wall then install the coping on this but this could turn out tricky unrolling the rubber roofing out. In theory everything is simple but in practice, thats a whole different ball game. Originally the engineer has a single ply roof with an overhang and a secret guttering but the clients not to keen on this.