richo106

Sorry to clarify, I have attached my first floor SE drawing and as you can see I have a lot of block walls that fly through the build. Leave 25mm off all these or can I go tighter on this. All block walls are planning to be dot/dabbed on the first floor

Is that 25mm off any brick wall? I was reading it depends on length of run etc. Is 25mm a safe cover all? When trimming up around the stairs I guess I make that flush?

That’s for mentioning that, I didn’t realise there was a different type of D4 glue Those screws look good! I was reading egger installation guide and they mentioned nails but would prefer screws

Update: I have spoken to guy who I got the MVHR system from and they don’t offer any sort of refund which I expected. It seemed to be a hasty decision to purchase it but it’s done now. Least I know I have to make it work I mentioned the installation issues that were raised and they said: ’The MVHR unit is insulated and can be installed into a cold roof, the 75mm ducting will need to run on top of the roof joist then rockwool can be poured over these pipes to hold the heat, at the moment I am seeing 300mm – 400mm’

Update: The joist company has done an updated layout drawing that shows noggins and restraints. Does this look ok? Thanks again @nod @PeterW

Regarding the edge trim, I have attached my layout and highlighted the areas that I will need edge trim for. Would you agree with this? Just so I can all z clips ordered The company haven't got back to me yet but planning to do it

That's good regarding the boards not needing a noggin I have emailed the posi joist company regarding the issues raised about the restraints and edge trim. I already have some z clips ready to support a couple of stud walls above If i don't get an answer this morning ill give them a ring Strongbacks will be installed shortly Many Thanks

When you say restraints….are they strongbacks? cheers

There is no noggins shown on my drawing at all (see attached) Am I right in thinking I need a noggin where the floorboard join? Thanks regarding the glue

Tempted to remove the velux window over the en-suite so I can build the "MVHR house" off the bedroom vaulted ceiling wall. Not sure how happy the mrs would be about that

Hi all This time next week the builders want me start installing Egger peel & clean 22mm T&G floorboards, i have downloaded the egger installation and happy with how it needs to be fixed. I have 75mm posi joists that are going to be installed at 400mm centres, I am pretty sure the layout created by the posi joist company would not have any thought for the floorboards to ensure they finish on a joint. I am guessing that I will have to install quite a few noggins What is the best way to reduce the amount of noggins needed and also the best way to install a noggin on a posi joist? How much glue you reckon is required per board/m2 etc just so i can make sure i order enough Many Thanks

In an ideal world we would use the equipment we have on site, I keep going back to the idea suggested by @Redbeard and creating a MVHR house within the loft. This would only be extra cost of the additional insulation to surround this and a bit of stud work And to negate all the ducts going through the cupboard i could stud out the wall in bedroom 2/dressing to take the pipes down to the ground floor and come out the correct side of the RSJ. Or run them straight across the hallway and into the kitchen missing the RSJ If I have air layer on my first floor ceiling could this potentially work?

This is my concern now that its very likely i won't be able to return any of it so going to have to make it work somehow To keep the cost down of the warm roof could I use knauf insulation rafter roll 32 with 50mm PIR over the top? On their calculator this would be a U value of 0.13. Is this acceptable for a roof?

Hi @Iceverge Thank you for the reply, you are correct that air tightness hasn't been planned from the start. With the rise of energy costs and a few chats with friends kind of persuaded me to go down this route. Regarding the ducts, i was planning on running the ducts passed the steel beam and into the kitchen area that way. This would cause them to take a slightly different route. All day I have been thinking about this and if I am wrong to go with MVHR, i am going to email the guy I got it off and see if he does any returns policy at all. I have measured up the roof area and i reckon there is around 114m2 of roof rafters that will need the insulation, and if i go with 120mm PIR & 50mm PIR it will cost the best part of £4500-£5000 just in materials Would also like to hear the opinions of others Regarding the other thoughts about the build, if you would like to private message me about this. I would very much like to hear your thoughts on this Thanks again

I really done appreciate all the replies and time taken to reply! I honestly have no idea where I would be without this forum so far

Regarding sectional drawings I haven’t got any, only drawings I have are architects drawing and structural engineers drawing no specific insulation levels. regarding designing out some expense, everything I do so far just seems to add cost so would be welcome to any items that could design out cost

Yes my apologies for any confusion, I meant 50mm under the rafters.

This was my first thought when I thought of warm roof. In my two front bedrooms I am planning on having vaulted ceilings. At the minute my plan for them was: 120mm PIR between the rafters, 50mm PIR over the top taped, vcl membrane and then plasterboarded. I am guessing there is a reason why I can’t do this in my loft space? Or would this be a suitable option? would there be a cheaper alternative to using 120mm PIR between the rafters? I have attached my 1st floor layout, the red area is a flat roof, all the rest is traditional pitched roof

You mean something like this for the vapour layer? Obviously some thought would be needed for the MVHR house

I have a meeting with the building later in the week, if it is not possible to have a warm roof for any reason. What is my next best option to help solve some of my issues with my MVHR unit being in the loft Many Thanks

Could just having insulation between the rafters work? Then an air tight membrane over the top?

Sorry to confirm, but in all your guys opinion would going for a warm roof be the best option? We are planning to have a couple of velux windows (over the bathrooms) and a large sky lantern on the landing flat roof Would this still work with these? Many Thanks

Where would I get this proper design input? Many Thanks

Is the warm part, adding the insulation DIY'able or would this be in the construction of the actually roof?

More than happy to explore the warm roof option as this is the time to do it Without me googling it this morning I didn't know warm/cold roof was such a thing What is a typical make up of a warm roof?