gravelld

Given that the very nature of this forum is that of one for self builders of varying levels of experience, it might be best to describe why something is a "ludicrous idea". Not everyone understands all the steps and risks involved in what turns out to be a complex project.

Hmmm. Ok, that rings a bell. Looked at them many years ago.

Well... I don't know. But I do know that Nibe et al sell their exhaust air HPs as a combined solution. It might be the ventilation levels are not enough to satisy a tight build. Yeah, I assumed the ventilation must be continually provided whether or not the compressor is running. A bit like in a A2W HP the CH pump and the pump between the HP exchangers can keep running if the compressor is off... (AIUI)

I have my fabric first retrofit checklist and rooms in the roof makes for a low score! 😉 Best way of fixing those types of roof structures is to take the covering off, imo. Has to be done to make EWI continuous with loft insulation anyway (in a cold roof). Thanks!

Interesting idea. I want to make it as simple as possible. Although exhaust air heat pumps were originally about DHW I think they now also cover space heating. But am I trying to pump to much energy through the ducts when the "air cannae take it". I guess it's down to the heat loss eventually...

Really interesting thread. We're looking at a renovation project at the moment with a late 70s forced air heating system. First priority would be upgrading the building fabric (and likely removing a lot of asbestos). But after that, it would be interesting to use the existing ducting. If we achieve good levels of airtightness, would it be possible to use an exhaust air heat pump to also combine ventilation?

I've used a lot of Blowerproof - but it's not a decorating paint. As @Sparrowhawk says it's more like a liquid plastic/resin which cures semi-hard and is flexible to movement, unlike decorating paint. You can get it in white and it can be overpainted or plastered. It's ideal for narrower spaces and where taping might be difficult e.g. around pipe penetrations. It's a lot more forgiving to install.

I chanced across this place on Monday on a visit to London. It's interesting but is more aimed at the undergrad I think. The normal high minded thoughts and some parts have a focus on retrofit but nothing really practical, i.e. how we make it affordable to the 99%. There are a few exhibits from manufacturers. Probably the best thing about it is Store Street Espresso is just up the road.

Google: site:buildhub.org.uk Baufritz

Good to see some high performance building going on in Leicestershire, we seem to not have that much about! Whereabouts in Leicestershire?

I'm not talking about replacing a lead valley with a GRP one - I'm just talking about going over the lead valley with a coat of the GRP. I have also used those flashing patches successfully, and they do stick so long as the lead is cleaned up nicely. But they are even more temporary I think! Yeah they are fine fissures/tears in the lead. I think this lead is about 25 years old. One of the roofers commented the runs were too long - they should be cut to maximum 1500mm runs, he does 1200.

We've got some holes in our lead valleys and want them fixed. Two roofers have recommended just coating them in liquid GRP. A final roofer said it doesn't last and we should put in a new lead work and valley. Does anyone have any experience of liquid GRP and how long it might last? Trying to weigh up the cost/benefit.

There's also Lunos, if that still exists.

I found what it is... it's one of these: https://www.victorianplumbing.co.uk/bristan-jute-mini-twinline-thermostatic-shower-valve-w-adjustable-riser-ceiling-fed I think the generic term is "ceiling fed". "Twinline" is Bristan's name for it... I think. But I can't see it on their website anymore, so maybe this design is obsolete.

Since switching to mains pressure hot water I need a new shower in one of our bathrooms. It currently has a digital mixer (the type in the loft which just has one output which goes to the shower) which incorporates a pump and requires gravity feed pressure. It's started leaking - it probably shouldn't have been reconnected to the mains pressure hot. I would prefer a standard thermostatic shower but that would require running more pipe. However, I think it might be possible to have a thermostatic shower with one feed... In a different bathroom I have a Bristan shower that has one knob for pressure and one for temperature. The controller stands off the wall and takes one feed pipe. In the loft (above the bathroom) the hot and cold are merged into one pipe - this one pipe then goes through the ceiling down into the bathroom and into the controller. This was also downstream of a pump, but I don't think the pump was necessary. They don't appear connected in any way. It's not a digital mixer - there's no mixer unit as such. There's just a Y junction where the hot and cold are merged. It's like a normal themostatic shower, but the hot/cold feeds aren't where the control knobs are. If we could merge the hot/cold in the loft, like with the shower above, that would give the best of both worlds. What are these types of shower called? I can't see it anywhere on the Bristan website.