MikeGrahamT21

Hi, Never seems to be a firm answer on this... We have 100mm joists with sleeper wall, which we will insulate with 100mm PIR, friction fit, and gaps filled with expanding foam. I have got some Tyvek Supro (breathable roofing felt) left over, and as its airtight to 50pa, I was going to use this across the top of the joists, before the OSB3 goes down. However I've just read online, that its more suitable to have a VCL above the joists, to stop any moist air going underneath. Ample ventilation under the floor and a decent gap. Would you say an airtight VCL may be the best option? Regards Mike

fair enough. I dropped on some Tyvek original tape other day for £13 a roll, which I thought was pretty decent, need some to finish off around the roof windows.

Wow, yeah £9 a roll is very good, I'm guessing thats not a price we can all pay? lol

If anyone is wanting breathable airtight membrane, rather than an AVCL, Tyvek Supro (i.e. Roofing Membrane), is actually airtight to 50pa (I think), so should be suitable and is reasonably cheap on ebay. http://www.dupont.co.uk/content/dam/assets/products-and-services/construction-materials/tyvek-building-envelope/Documentation/Technical-Datasheets/TDS-DuPont-Tyvek-Supro-and-Supro-Plus.pdf Resistance to penetration of air EN 12114 m³/(m² h 50Pa) - - 0,25 (Maximum) Compared with a true air barrier: Air Permeance EN 12114 0.01m3/m2/hr @50Pa Kingspan Nilvent is also classed as airtight. They all claim airtight at normal building pressures 50pa. I plan on using this under the floor boards to save me the nightmare of having to seal every little bit between the joists, and then lap up the wall, and bond to the wall itself, it'll then get covered up by plaster and skirting board.

Whats the airstop stuff like Dave? Read some bad reviews about it not sticking, as I was going to buy some for my windows.

Actually to stop this from happening, a fire retardant membrane behind should sort this out, which will kill the flames on contact, so may need a combination of both membrane and coating.

No i can appreciate that, don't think i'd want to either. Timber is going to be screwed on, so I guess i could always unscrew it to repaint if needs be.

Found this one, which seems to fit the bill. No undercoat required (undercoats seem to be the most expensive) http://www.fireproofspray.co.uk/flametect-c-wd-for-wood-clear-flame-retardant-68-p.asp And you get a certificate with it for if BC ask.

Yeah its only a single storey extension, i'll do some more research on the coatings.

Yeah 600 wide, I think the timber alone will be fine, its never going to get touched once up so it should be fine.

I'm guessing the treated timber will be hard to come by and expensive when I do. Varnish is likely the way to go with this one and re-treat and and when required. Yeah I've thought about the aesthetic appeal, which to be honest is why I want to go down this route. Timber I'm looking at is 19mm x 38mm/50mm PSE, which ends up 14mm thick, so overall probably about the same as a plasterboard and plaster, no problems room looking darker, as its got a lot of glazing anyway. Looking at a few of the treatments online, they all say effective for the lifetime of the timber, so sounds good to me

Been thinking about different finishes for the vaulted ceiling in our new extension, and I've come up with the idea of timber cladding with gaps in between (a bit like what people use on the outside of buildings), think it will look nice in there, and a little different from the usual plaster. Obviously the roof trusses are timber, and the insulation is PIR with foil face. Question is, do I need to have any sort of fire retardant barrier behind the timber cladding on a ceiling? I've seen some on the web for about £100 a roll. I'd ask building control, but I doubt they would understand the concept of not using plasterboard lol

I will indeed, thanks for your input as always. Will do!

Yeah I agree mate! I'd rather pay the extra for solid brass. Well, I think my plan is set. Just need my wife to get better now, so I can knock through into the extension and then start all of this work, so it may not happen this year, but hopefully it will, as that means shes better!

The ones I've chosen are solid brass stems with chrome coating on them, and a pushfit connector, a little more expensive but should look nicer overall, then I'll put some chrome pipe cover on the little section of copper which will be showing, or paint it with some kind of chrome paint, I'll make sure it looks good either way :-) Infact, I've even found a white one: https://www.plumbnation.co.uk/site/hep2o-spigot-elbows/ but they are plastic, i'd rather the brass one for the compression as you say

it would be good to know a realistic ball park figure without having to get a company out to do a full quote. Our main issue with a dormer though is lack of space to put stairs, we could make it work but it would be hard work, we don't have a massive amount of square meterage, though lots of houses on the estate have dormers, its often in the slightly larger version of our house, not always, but most of the time. We would have to lose the 2nd bedroom for the staircase, so would need at least 2 bedrooms upstairs, gaining us 1 extra overall, ideally we'd get 2 bedrooms and 1 shower room upstairs if we went that way. I'm up for considering anything, my main concern with dormer is whether the planning department would allow flat roof mounted solar panels, if they won't, then we are limited to a single dormer, and would have to move 8 solar panels on to the utility roof (i designed it to take these anyway, plus its south facing)

no no, it was just a wild guess, based upon odd things i've read in Magazines. I know the materials aren't that much, its the labour. House is a 2bed semi bungalow, what do you reckon rough price? This would be for a full dormer conversion, double preferably, GRP roof, with 8x mounting for solar panels (if allowed by LA), probably 4x triple glazed windows, and cedar cladding to the outside.

Yeah I totally get it, i've looked into EWI for the whole house as it stands now, and the amount it costs is crazy compared to what we would save. I did the EWI myself on an extension i built, it was straight forward enough, but really hard work, and still cost a lot of money, but less than what it would have done. Yeah I thought about it, but I don't think the savings would be enough to justify it, plus it would be nice to have extra garden! :-) I read that planning wasn't required for 2 in to 1, but was for 1 into 2, but i have no firm answer on that. OK, EPC is quite cheap i guess so thats no problems. Another thing i've just thought about, we have solar panels with FiT, would any of this affect that?

Ah right, so its not set in stone that it is required then. Its certainly possible in these houses, but it is more ££, and if we have to buy cash, there won't be a lot of ££ left to do things like expensive EWI.

Originally we were thinking about adding a dormer conversion to our 2 bed bungalow (double if possible), which probably wouldn't be practical for us for a number of reasons, until I had the thought of buying the house which is attached to ours when it became available, I've known the people who live there all my life, and a couple of years ago when i was building an extension on the back of ours, the lady said she'd ask her Son to sell it us cheap so we can knock through into it, and I never thought any more of it really, until last year. Recently the lady has passed away, leaving her husband who is in his 70's, so I want to be as ready as I can be to buy as and when it becomes available, which may well not be for a very long time, but could also be soon, you just never know, we hadn't expected her passing away last year. House will probably be around the 100k mark, going on the state of it (poor) and other house sale prices in area. I reckon a dormer on ours would set us back at least 40k all done, which is what made me thinking about putting that 40k to better use, and gaining far more. Am I right in thinking that we wouldn't be able to get a mortgage on the house next door due to our plans? I've also read that you just can't buy an adjoining property with a mortgage? Now as I believe it, no planning is involved making 2 houses into 1, building control is required for the structural conversion as would be expected. Because of the major renovation, would we have to upgrade both houses to modern standards of insulation? This is something we want to do anyway for obvious reasons, but want to factor it into the price, as insulation prices aren't going to be going down any time soon, and to get it to modern standards would require external wall insulation. Any ideas/input from anyone who has perhaps done this themselves in the past would be brill :-) Until the time comes, we'll just keep saving, we aren't big spenders anyway!

Forget the female elbows, I'm going to use the push fit stem elbows, a small section of copper, then a 15-16 converter hidden behind the rad, job done!

Think i'll buy a cheap 15mm female elbow, i've got a spare TRV in the garage, and I'll have a mess with it to see where it lands. Obviously I can't test for leaks, but it should give me an idea if it will fall where i want it to, though i'm guessing via sods law, it won't!

OK, the only rad which will be affected by the 90mm will be the living room one, and it has nothing in front of it. Bedroom one has plenty of space above it, so I'll raise it 50mm when i put the new one in to go to 150mm. Found these for the verticals, with high heat output: https://www.ebay.co.uk/itm/Vertical-Designer-Radiator-Oval-Column-Tall-Upright-Central-Heating-Radiators-UK/201641074281?ssPageName=STRK%3AMEBIDX%3AIT&var=500899344119&_trksid=p2060353.m1438.l2649 No mention of brand really though. The elbows certainly sound challenging, I guess a stem elbow is still the best option if I can find a 16x2 version, which I haven't so far. I have had a look at stelrads installation instructions, and it seems you can locate the flow TRV at the top of the rad, making the TRV in a better position for sensing temperature (being off the floor), what do you think about that, or shall i just stick to the norm of both at the bottom? I just need to know before I order any smart TRV's, as they come in horizontal and vertical types EDIT: Just found these: http://www.johnguest.com/speedfit/product/12-16-20mm-size-fittings/stem-elbow-3/ Seem to come in 16mm push fit, would that work with MLCP? Cancel the edit, you can't buy them in the UK

I've just read on here: https://www.emergencyplumber.uk.com/plumbing/best-radiators/ that radiators should be a minimum of 150mm above floor level, for convection to be at its best, just checked what ours are currently and they are around 90mm, what do you think about this recommendation, worth taking note or not?

I was going to buy stelrad softline compact radiators, based on what Nick (i think it was you) said on another post about them being good quality, but I've noticed that for the same size (i.e. 600 x 600) other manufacturers seem to have the same guarantee buy more output W, which potentially means I can get a smaller radiator for the same output. Would you stick with the stelrad?