MikeGrahamT21

Just remember to pay maximum attention to airtightness, to ensure as efficient running as possible for the MVHR, its fiddly time consuming detail for sure, but its going to be there doing its job for many years to come, and if you have the opportunity before you get to second fix, get an air test done, to detect any small leaks which aren't obvious, again worth its money in the long run.

If you can do MVHR, do it, as it is far and above any other type of ventilation method. Remember, trickle vents only work on days when there is wind, unless you have a dMEV setup, however this is basically like a poor MVHR which doesn't recover any heat.

Put as many in as you can (obviously keep sensible), its cheap to run, and they have far more uses than just for general networking, can also be used to transmit all types of signals using x-over ethernet converters (where x is what you want to transmit), one such type is HDMI over Ethernet which can be very useful, since long HDMI cables tend to not fare very well. Make sure you pay the extra for good quality cable, LSOH (Low Smoke Zero Halogen), and really ensure you are buying solid core cables, and not stranded!

Not strictly speaking true, but not truly airtight. Something like Tyvek Supro is airtight to 50pa

If its a breathable membrane, that means moisture can pass through, so I'm guessing in this instance it wouldn't be of any use at all. You'll need a full AVCL to stop moisture from passing.

Absolutely, going with the thickest pipe insulation, the water bylaw stuff just to be sure, and to make sure we have hardly any heat loss from the CH too.

In some places they are in outer walls, and in others internal walls. Airbricks are doubles, so they are the same height as the 2 brick sleepers, and the bottom of the airbrick is the oversite concrete, so no room for manoeuvre.

Not thought of that, how about the DPC on the house though, as this is the same level as where the timber is currently sat, plus it would also decrease the air gap underneath the timber to around 75mm, below the 150mm min which is required, which is what its at currently.

Yeah I had also considered this too, sub base is already concrete, so would just need insulation and then screed. I went away from this idea, as all of the heating pipes and electric cables run under there, would make it a large project and a much larger cost, so going to stick with the timber for that reason.

Friction fit, with a bit of expanding foam in any gaps, theres not enough room below the joists to get the screwdriver drill under there to fix anything to the underside, plus the PIR will poke through as below, i've done 1 room already and that worked well, but I didn't know about AVCL's back then. I'm using the AVCL more for the airtightness factor, as you can never seal 100% without one in my opinion. Yeah joists going too, i know the new ones are 95mm, so the PIR will protrude the bottom by 5mm, no point getting 90mm PIR as its more expensive than the 100mm.

If it wasn’t for needing to replace the wood I’d do this, but need to rip it all out, clean underneath and 100mm PIR in between joists, had a look at BG Plank system too, but it makes so little difference to overall u value it’s just not worth the expense. Going to put AVCL under floorboards too and stick it to masonry behind the skirting as an upgrade

This is only single storey house, but no it’s just brick, dpc and then joists, had a look on google earlier and found both variants so I guess it probably varies around the country and each build, which materials they had more of. We’re 68 bungalow. I’m kind of glad there is no wood there at moment as we are still stripping out all of the woodworm damaged stuff!

Yeah I was annoyed by that too, i even rung them about it and they claimed thats how much it costs them, needless to say I didn't order via them. I got it from these... http://munsterhrv.com/shop/index.php?main_page=product_info&products_id=123 The other brand i've used is airstop (https://www.airstop.co.uk/airstop-tapes-c1775), both products seems to do the job well, if anything the airstop stuff is even more sticky but doesn't seem quite as thick.

Yeah there are airbricks to the outside, and you are right, the bottom of the joists will be on show to this. So not much point?? Saves me work i guess if not, just trying to make it the best it can be

Hi, Our bungalow is blessed with sleeper walls, and 100mm joists, and to increase to 200mm joists, would be far too much work digging out. At present the sleeper wall is simply created from bricks, with a DPC, and then the timber joists on top of that. In an effort to get the thermal bridge as small as possible, would it be worth while taking the top row of bricks off of the sleeper wall, adding a new DPC on top of the remaining brick, and installing a timber for the joists to sit on? Regards Mike

I did this again the other day, and ensured that all of the materials had the correct Mu values for water vapour, with a 20mm internal VCL via the Marmox it came down to around 2days of condensate a year, which is absolutely fine, don't think i'll get it any lower than that without losing too much space inside. EDIT: Entered correct details for the Marmox and we are now condensate free, definitely the way to go.

BuildDesk, that was the one I couldn't think of. I ran it through there and it said no risk. BS5250 is the one which building control accept isn't it? Maybe its worth going with the marmox just to be on the safe side, like i say aside from the financial aspect, it doesn't make much difference. Just had a play with u-wurt, that seems quite extreme, even with the vapour check it reckons 55 days drying time per year, and oddly how a house is normally built is even worse!

Hi, Wanting to try and get a firm answer on this, I've got a solution for both, however the 'requires VCL' method is more expensive. I have applied 90mm of EPS external wall insulation to a block - 100mm filled cavity - block contruction building. I've ran some simulations using WUFI and another app i can't even remember the name of, and both suggested even with the worst possible humidity inside, the construction would be fine and free of condensation risk, however its always been playing on my mind that these apps just might be wrong! lol So if I do need a VCL, I plan to dry line the interior with a 6mm Marmox multi board (which has integral XPS as part of the construction) and then these can be direct plastered. If I don't need a VCL, i'll just wet plaster the walls, or dry line using normal plasterboard, though would probably do it right, and wet plaster. Let me know your thoughts. Mike

We always used to wash at 30C, with 60C for bedding, but I recently discovered a new mode on our washer, Eco Clean 20, not only lower temp, but also uses half the amount of water the the other mode used! We put in the anti-bacterial liquid to kill any nasties, which we always did anyway, and that works down to 15C, i've not noticed any difference in terms of wash quality. Just need to get me a heat pump dryer now, then i'll be able to run it off the PV with zero cost quite easily.

Still seems a bit on the high side for what we got quoted. Spec i asked for was: Eurocell Modus which is 75mm profile (4/16/4/16/4 Optiwhite Pilkington KS Pilkington KS Argon SuperSpacer Premium Full Thermal A++ 31 0.8U) Price was £386, and window size (2 side openers, 1 top, 1 fixed pane) is roughly 1.7m2, though it is just a price on an email, so theres the chance they could have quoted wrong, but I would hope not since i gave them the exact spec.

Those definitely won't be BS5250, dont think IP20 is high enough for it, if airtightness is a concern to you. Something like these may be more appropriate? https://www.amazon.co.uk/MiniSun-Brushed-Recessed-Downlights-Spotlights/dp/B01535DAVC

LED GU10's still get warm, but I wouldn't say hot, you can certainly hold them. The only negative of having insulation packed round the fitting is the LED likely won't last as long as its stated run time, but thats hardly a game changer given their cost now. Ensure they are BS5250 (if I remember right, for airtightness), and fire rated fittings and personally I don't see an issue, but if you are concerned check with BCO (though they likely won't care anyway).

Fingers crossed. She has the NHS's finest working on her at the moment, we are so thankful for the NHS as we know the costs for all the treaments and admissions she's had in the past 12 months run well over £1m! We are in a 1960's bungalow, i've made a lot of improvements already, there is no noticeable air flow from leaks, but I know the leaks exist, especially behind the kitchen cabinets at floor level. I'm hoping the air purifier will have a positive impact though, time will tell I suppose. Yeah I totally know what you mean by the 'don't look that sick', she gets it all the time. Her lungs are only a tiny part of her complications though, she has a rare genetic disorder with a subset of other nasties which make her totally unique in the world. Life is tough, but we just keep smiling :-) I hope the new house does you the world of good, I can't see it not doing with all the research which has gone in.

Yeah me also, though i am a constant worrier anyway. Thanks for your kind thoughts, she's had a lot of difficulties since last year, firstly with a multi drug resistant pseudomonas infection, and now with aspergillus! Following a quick google the other day, I discovered that the pseudomonas was actually holding the aspergillus back, now thats gone, its having a party in there! After much consideration of MVHR, and I must have been looking into it now for over 2 years, its not do-able for us at the moment, partly because we just aren't airtight enough yet, and partly because one of our lovely neighbours has a wood burning stove which pollutes the street, the airtighting is fairly easy but time consuming to fix, the smoke issue i've not been able to get round as yet, so for now I've invested in 2 BlueAir Blue Pure 411's which filter down to 0.1micron (anything less and mold spores are likely to get through, aspergillus for example can be 0.2micron), and i've bought a FooBot to keep a visual check on things.

I'm probably going to go against the grain here, but... Have you considered Eurocell's Modus Range? 75mm profile, and with the correct glass will get you a Uw of 0.81, for a pretty reasonable price. I got a quote for a Window which we had made by another supplier who use Liniar profile, and ended up a 1.1Uw, and Eurocell were cheaper! The Modus Profile is also suitable for passivehouse, but isn't a certified component, its been designed with PH in mind. Pretty sure you'd get a good discount on them too.