jfb

probably easiest to post a diagram with a scale to make it easier to see what is going on. Presumably the length of the proposed extension is 7.4m which exceeds the 6m max length for PD for a terraced house. (detached is 8m limit I believe). So you could build to the same length of the existing 6m long room under PD but to go further you need to apply for planning.

I ended up replacing the whole pipe that goes from tank to this chamber. Probably for the best as it wasn’t in the best state! Thanks for all the advice

It is an overflow chamber for the septic tank. I’ve replaced a failed pipe with the plastic. Previous pipe came out from the very bottom of the chamber and my new one comes in just above it. the whole chamber has been buried under a fair bit of earth so would require a fair bit of landscaping or raising if it was to become an inspection chamber.

Just shingle and perforated pipe

I believe that for a clay soil a geotextile membrane won’t help much since the membrane itself is prone to clogging up. Sandy soil is much more suited to a membrane.

I'm trying to join these two pipes together. The 110mm plastic pipe is about 200mm below the original clay pipe. Any ideas on the best way to join the two? I could chip away round the clay pipe enough to get a rubber collar around it i guess. And what about once I can get around the clay pipe - is it just a question of a couple of angled 110mm joints or is there some flexible rubber option that might do the job easier?

I wouldn't have thought they need anything. Once it is established as a dwelling it is unlikely to go mouldy like it has. See what you can do to brush the mould off now and then see how it behaves once in use.

You can get tape that sticks to the timber and then you render over the bit of tape on the wall for airtightness. Why not use glassfibre or rockwool? Much easier to fit than rigid baords.

I have done a couple of my own roof structures myself. Used a normal sprayer and permethrin. More ventilation the better, make sure the timber is dry so it soaks up as much as it can. Did about 3 or 4 sprays. Proper mask with filters, gloves, goggles and painters disposable overalls. I never looked into getting quotes so can’t help on that.

Get the landlord to sort it out?

I might be wrong but I think minimum U-value for domestic is 0.16. For non domestic it is 0.22. These figures are for new build, not renovation but I believe a barn conversion is effectively a new build - but I could be wrong. can you not just go for 100mm external insulation? No need for internal insulation then. Then either render straight onto the wall or vcl/ battens for service void / plasterboard.

What are you planning on constructing the dormer sides out of? for PD I believe that it should match the existing roof (so if clay tiles then vertically hung clay tiles).

Parge coat. Are you internally insulating or externally?

What is the coil in the MVHR? Does that do both cooling and heating via the MVHR? And presumably require extra pipework to the MVHR?

I haven't looked at prices recently but i remember when I bought some last that Steicotherm boards (for plastic fixing to walls) were considerably cheaper than other options. But I don't know off hand how they compare to Pavatex Isolair. And you can still chase cables into the boards, put some capping over and then render.

Do their heat pumps work in reverse for cooling?

a. yes : better to use lime but for a small area probably won't matter using gypsum b. no c. definitely no d. no original lime render is performing a role as an airtight layer so bet to leave it in place. The other overall option if the existing render is reasonably flat is to use woodfibre boards that are fixed directly to the walls without any need for studs with a lime render on top. But I am guessing it might be a bit late to consider that.

Very Nice

Put a tilt fillet under the last bit of membrane so that it can’t droop and allow water to pool there.

Is there an electric shower?

I’m not an expert on parging but I believe it is pretty diy friendly. I think you can make up a wet slurry and then broom it on to the walls. Someone with more experience might be able to chip in.

Are you planning on a parge coat? No reason why block construction can’t be airtight - just needs attention to detail where different materials meet (as you are considering with the Tony tray) and some sort of render/parge coat on the blocks. Standard builder dot and dab won’t be airtight unless real care is taken by the builders (which is unlikely).

Does anyone really notice the quality improvement from 4K to 8k? I mean even up to 4K seems pretty marginal at best. Just so we can all use more power. The joy of progress! then again, it’s your house so do whatever you want!

Yes understood. And thanks a lot.

Thanks for the reply. Well we haven't signed a new contract yet but was thinking of the same year contract as before but with the different year on it. But I see the issue with regards the deposit/DPS. Don't really want to just let it roll over so maybe I should go for your idea of an addendum to the original contract. Might I be able to have a look at the addendum you use? cheers john