deuce22

So would a heavier insulation, whether it was marketed for thermal or accoustic, have better sound proofing properties? The plasterer has just told me that he uses standard boards, but doubles them up, rather than using accoustic boards. The double standard board gives better density and is also cheaper. I just want to understand if density is the main requirment for sound proofing. Thanks.

Hi. I am looking for some clarification. Does acoustic insulation have different properties over thermal insulation. I’ve been told, that for soundproofing, it is all about density. If an insulation that is marketed as accoustic, weighs 10kg m3 and an insulation that is marketed as thermal, weighs 15kg m3, will the thermal insulation provide better soundproofing? Thanks.

No, those boards are not there. They've used 200mm+ screws and fixed vertical battens, through the PIR and into the rafter.

No. Im not a roofer, but have an idea of how it all works. I'm now realising that the OSB should have been laid on top of the rafters, with the VCL fitted to this.

roof tile counter batten with breather membrane between 150mm PIR insulation 8x2 rafter with mineral wool between

The ceiling is not up yet. I've spoken with a company that has advised to do the following. Fit a VCL to the underside of the rafters, board and skim, use sealed downlights and seal them to the ceiling with silicone, then use a paint on VCL to the whole ceiling before emulsion. I like the idea of the spotlight shrouds, where do you get these from? Starting to get fed up with tradesmen, just had to go around re-fiting all the door straps into the concrete infill (ICF construction), the fitter used wood screws into the foam only, an almost 1/2 tonned bifold, being held in place by bits of spray foam. Thanks for the help.

Hi. I am looking for some advice on an issue I have with my roof. The roofers have fitted a warm pitched roof and told me that the vapour barrier gets fitted on the underside of the rafters. I have vaulted ceilings on the top floor and a lot of spots and sprinkler heads. I’m now finding out that the vapour barrier should have been fitted to the boards above the rafters. Is there a way for me to fit the vapour barrier underneath, without having a lot of areas where condensation can pass through? Thanks.

Thanks for all your help. I've thought against doing all the door openings like this now. I'll just do the 2 that are needed and the rest will be standard doors. Thanks.

Thanks Mike. I didn't think about cleaning or maintanance. Maybe I will regret putiing them in.

Thanks Thorfun for the advice. I've just spoken with the chippie again and he has given me a bit more info. He said that the kits vary in thickness, but as he doesnt use the steel wrapped timber studs, he works with a 120mm thick stud wall. He rips down all the timber to 35mm on the table saw, fixes these top and bottom, which gives a 50mm void for the door. He believes that doing it this way gives a sturdier wall, compared to the kits and costs a fraction of the costs. This seems pretty straight forward for me, but I'm wondering if this wall will be sturdy enough. I may just try 1 and see, unless somebody can confirm it on here. I'm wondering why pipes, cables and sockets/switches/back boxes can't be used between the 35mm stud or is it that your kits use much thinner steel wrapped studs.

Hi. I am looking for some advice on pocket sliding doors. I am in the process of putting all the stud walls up in a new build and trying to decide on whether to use standard or sliding doors. I have 15 doors in total and the kits I’ve looked at are around £200. I don’t really won’t to pay 3k for the kits, so if this is the only option, I’ll go down the standard door route. I had a quick chat with a carpenter and he said you don’t need the kits, just good quality parts/fixings. I just want to know if these can be framed without the kit and if so, are they still quality, or is it just a bodge job. Thanks.

Ok, so there's no comparison really. Why would the SAP company need to know, that I'm using MVHR over intermitent fans?

Thanks both for the explanation. I have not had a blower test done, just sent drawings to the company and they've sent back a spec for it. So it's not just as simple as doubling your 160m2 house and that would almost be sufficient for my 345m2 house? How does a MVHR differ from the intermitent fans I've been told to install?

Hi. I've been given my SAP calculations and it states that I should be using intermitent extract fans in the kitchen and bathrooms. I'll be starting on first fix shortly and so I'm going through things now. I've been told that the fans wont work properly as I dont have trickle vent in the windows, is this correct? If that is the case, the next option is MVHR. Somebody I know have just installed this in a 200m2 property and it has cost him approx £1500. My house is around 115m2 per floor over 3 floors (345m2), so I assumed it would cost me double (around 3k). I've just had a spec from bpc ventilation and the cost for the two options is between 5-5.5k. I've been told by somebody to have 1 unit for each floor as this will be more cost effective and if one fails it doesn't shut it down for the whole house. I'm looking for advice on what is the best option and what it should roughly cost per m2. Thanks.

andyscotland I'll give Celotex a call and see what they say. I've spoken with Kingspan and they said that there was no need to vent the roof with the current spec. Thanks.

PeterW Due to what has been discussed here and from my own experience I don't trust what any tradesmen say, Ive been ripped off a couple of times and also been talked into doing some things that I now realise is not the right way and has cost me more money to correct it. I will be in this property for at least 5 years, but nobody knows whats around the corner, I could be here longer. I want it to be as comfortable and as efficient as possible for whilst I'm living here, but also want to do it in the best way for anybody that buys it in the future. Is there a big benefit to having 2x 180l over 1x 300l? Iceverge ICF is 67mm in and out. I was either going to use Nudura or Jackon. The salesmen for Nudura told me that 67mm is the exact amount that is needed and any thicker is a small return on investment. Jackon ICF was 50mm inside and up to 200mm outside, when I mentioned this to Nudura they said it wasn't needed. However, Nudura has now added another system that incorporates thicker insulation on the outside, so he was obviously talking crap. I haven't even looked into air tightness. There are quite a few openings. Out of 254m2 of external walls, 64m2 are doors and windows. It is an equal L shape. ReedRichards Is the 2862 kwh, the same as 2862 units of electric?

ProDave I understand that the electric coming from solar will be used for anything electric in the house, not just on the HP, but I wouldn't bother installing PV if I wasn't installing a HP, so I'm combining them together. ReedRichards So how many KW over the year do you think you save through solar?

ReedRichards So in your experience there's no benefit to installing solar to reduce bills from the HP? Have you got storage batteries as well? PeterW I didn't think it went on what my requirements are, I thought it was on the size of the house and how many bathrooms there are. It has 5 bathrooms, a utility room with sink and shower and kitchen. There is only myself, wife and child living there, but I have family that will stay multiple times per year. Our DHW requirements are not that much, but if a larger family moved here in the future, their requirements may be different. I started this build 3 years ago and have about another year before it's all complete, the plan was to have it complete in 2 years. This won't be my final property as I have an opportunity to live on a small holding in 5 years time, so i will eventually be selling this.

nod Saving money must be one of the top reasons for people installing these. Why would you pay more for something at the start to then pay the same or possibly more to run? When I started this build 3 years ago, the plan was to install a heat only boiler with 300l cylinder, run off gas. ProDave It is a new build constructed from Nudura ICF, 150mm PIR in floor, warm/hybrid roof with 150mm PIR, 200mm mineral wool between rafters. The boiler and cylinder I was going to install, was £3000 and this HE I mentioned, said he could do a HP for around £8/9000 and then get the £5000 grant. However I should then install PV to counter act the high running costs. This would add another £4/5000, so between £7/9000 for heat pump and PV and £3000 for gas + plus connection.

PeterW That's what I was thinking, surely a small cylinder in one of those combo boilers isn't sufficient for 5 bathrooms. JohnMo I was thinking of installing solar if I go down the ASHP route. billt I've joined an ASHP group and there is a lot of unhappy people, one person is paying £20 per day to run as it wasn't set up properly. ReedRichards I was planning on installing a heating loop, but watched a video on youtube where the calculations were done and it cost a lot to have these running all year.

I'm wondering whether to install an ASHP and would like to get some feedback from others on whether these are actually worth it. I have a 350m2 property over 3 floors and was planning to use underfloor heating on each floor. I've read quite a lot and have noticed that although they are a greener choice, they are not as efficient as gas and in some cases ridiculously expensive. A heating engineer that fits these have told me to install a heat only boiler and cylinder or a combo storage boiler. What are your opinions about this? Thanks.

I am coming to the end of fitting the insulation on top and I'm not too confident in this setup. I was thinking of adding the mineral wool in between and then more PIR underneath the rafters. Would this have any benefit to stopping condensation? Who would do a condensation risk analysis?

Definitely worth checking. I lived in a property years ago and on very cold days, ice would form in the the roof space and you'd here it cracking as the day warmed. That is the last thing I would want on a new build. Thanks for pointing it out.

I've just spoken with, both Kingspan and Celotex and they've both stated that it won't be an issue with condensation as its only 150mm.

I haven't got a cross section. I'm not trying to hit a specific U value. I asked the SAP company to get it as low as possible with the materials I was using and the depth of the rafters. I increased to 8x2s rather than 7x2s that were specified, due to their advice. These calculations were completed about 12 months ago and not one person has made any comments on this. I've never used this method before, I normally fill, in between and below rafters. I'll speak with a manufacturer today and see what they say. Thanks.