Gone West

Welcome to the forum, ask away, and good luck with the build.

So as far as you know it is still possible to fit a DIY PV system and have it signed off by an electrician but just not be able to claim for anything. Is that UK wide?

@Samhelliwell Congratulations, nice looking house.

This is the question from 2014. I'm struggling to get my head round the physics (is that the right word?) of a timber frame construction, so you will have to bare with me on this one ---- so looking on a typica timber frame wall build up, 1 - plaster board layer 2 - a vapour impermeable layer (this stops the water vapour inside the house being pushed, pulled or otherwise drawn into the wall construction and hence stops condensation within the wall. 3- the timber frame and insulation 4 - wall sheathing 5 - a wind proof breathable layer (this is to allow any moisture within the wall to exit into the big wide world). 6 - a rain shield layer of some sort, cladding, bricks or block (rendered). So do we need a sheathing layer and the wind proof breathable layer? What exactly are we trying to achieve? These are the full answers from Tom Foster. 1 - yes 2 - leave it out altogether - although still mainstream, recent research, WUFI modelling and bitter experience shows that vapour resistance at this (or any) point in the wall buildup is BAD. It's a myth that water vapour originating from inside is the problem in walls - walls can't help containing enormous amounts of moisture, hopefully safely in vapour form, not condensing to liquid at any point - and 95% of that originates from outside and ebbs and flows diurnally and seasonally. Don't try to block it - the drying out needs to happen both outward and inward. An inboard VCL halves the drying potential of the wall, which may never dry out, but increase its water content year by year. VCLs used to work, still just do for mere Bldgs Regs levels of insulation, but accidentally IMO, as an air barrier rather than as a vapour barrier as everyone imagined. Now, with v high levels of insulation, VCLs are bad news. 3 - yes - but only vapour permeable insulation i.e. not closed cell PIR, PUR etc. 4 - yes 4a - Now you need more vapour permeable insulation, right across the external face including the studs, which on the system you describe are a straight-through uninsulated thermal bridge. External insulation will almost entirely kill that bridge. You need 250-300mm of insulation; unless you have studs that deep, it can't all go between the studs; part must be in additional layer outside the sheathing. 5 - yes 6 - but masonry will require an outboard foundation, so vastly increasing your foundation dig, muck-away costs, lots more concrete, greater effective 'footprint'. Cladding will need to be hung from the eaves. Instead of both 5 and 6, patent thin-coat render direct on the external insulation is by far the cheapest. You need a layer that's impermeable to air (but very permeable to vapour) at some point in the sandwich - doesn't matter where. In addition a windproof layer outboard, if your outboard insulation is fluffy or has an 'open' surface - EPS is a little bit 'open' so prob needs that; PIR/PUR are not 'open' so don't need that. This windproof layer is usually also the 'breather felt' layer, laid close fitting at well lapped joints. Don't trust sticky tapes anywhere. The breather felt is well enough water proof to catch any water that may get thro the rain shield. It must be very impermeable to vapour; it won't be very air-impermeable but good enough to keep blasts of wind off the insulation face. Don't take my word for all this unless paying me a consultancy fee - check it to your own satisfaction.

It was the same for us. At seven weeks I went in and asked if the application was likely to be approved and they hadn't looked at it either. The excuse was loss of staff and having to sort out a new planning policy. They ended up refusing everything and after appeal we went to committee and won unanimously.

Could you make a small perspex window in the cover?

Just check you're comparing like with like. Does £1000/m2 include foundations? If so is it an average price for foundations, getting out of the ground can vary enormously.

I used a roll of s/s wire wool used to fill exhaust silencers on racing cars. Can be bought quite cheaply.

So the question for you is, do you want all the hassle of doing a self build to be marginally better off on the valuation at the end.

I would agree with figs. 4 & 7 but only if the window ventilation can be carried out every day. It is possible to purge the warm air over night but if you are away and not able to do so the heat will build up inside the house and it will take along time for the fabric of the house to cool down in the same way as it takes time to warm up a cold house using air heating only.

We have a small area of South facing glazing and it doesn't currently have an overhang. I will be adding a brise soleil which will reduce solar gain in May, June and July. The worst area for us is the large glazed gable facing WNW which has solar gain in May, June and July late in the day and to which we had external solar film applied. This has worked well. Your best option is built in automated external blinds or SageGlass.

Ours isn't photochromatic nor I think plain tinted. I was told that in order to have the film, it must not have a mirror finish and must be not be noticeable. We went for Clearview Vista 80X because it was the closest to meeting those criteria. It is very effective, but expensive, and if the photochromatic film was more expensive I couldn't be tempted. Clearview Vista 80X Total solar energy rejected - 45% (55% on double glazing) Visible Light Transmission - 77% Visible Light Reflection - 8% Ultraviolet Transmission <0.1% Glare Reduction - 12%

Yes I was replying to Dave and the BCO wasn't interested in ours.

I don't understand the problem. Ours is standard 720mm base units + 150mm plinth + 30mm granite.

I was thinking more Devon/Somerset. It's a long way to the tip of Cornwall.

I'd like a bungalow like that in the West Country, I wouldn't convert it though, just to live in.

Sounds like progress has been made, that's good.

Welcome to the forum and good luck with the project.

I banged our Brabantia ground spike into a temporary position twelve years ago and it's still nice and firm. I will move it this year though, to it's permanent position.

Half the price of Internorm.

Possibly, depends what you want and what you're comparing with.

They can be better than wood. We have Rehau Geneo frames which are fibre reinforced plastic which means there is no steel required. The sections are foam filled and they are better than PH requirement.

The chap who did our plastering has given up plastering due to shoulder damage, only in his thirties as well.

The granite worktop supplier/fitter just cut the slots in the underside of the granite and I fitted the sinks. It was straightforward.

They've been in use for over a year now without any problems. Probably fatal saying that though.