Triggaaar

Thank you for the reply. We have Venetian blinds at the front of the house. They let light in, but offer privacy. A much better alternative to net curtains IMO. We certainly don't want anything like that at the back though. We want to enjoy the view and let in lots of light. I don't think the wire option would work for us, as the span is longer, but it sounds very similar to having a flush curtain rail in the ceiling. Your grey voile panels are about 1.5m wide each - how many of them do you have, and how much space do they take up when pushed to the side?

I hope it's ok to put this here, I couldn't find anywhere else that seemed appropriate. I'm planning to put 7m x 2.75m sliding glass doors in our new kitchen extension. They will be floor to ceiling and should look fantastic. However, I cannot come up with a suitable method of covering them. The room is east-south-east facing. Privacy isn't a big issue. We're overlooked a bit by some student accommodation, but it's a couple of hundred feet away and not an issue. Option 1) - Don't cover them. This is the cheapest option In summer, they will look good. It's not dark outside much, so the only negative is that the sunlight might be a bit strong in the morning (the sun rises fairly quickly though). The problem is that from October to March it's dark outside a lot of the time, and I imagine a large expanse of glass will look a bit stark. Some material would help soften the area and make it feel more cosy. Option 2) - Electric roller blinds a) In a box in front of the doors. In my mind, this isn't an attractive solution, and takes away from how nice the doors will look when not covered. Instead of a box, we could have the ceiling plastering extended vertically down for 5" to cover where the blinds would go. I imagine the effect would be similar to a box. b) In the ceiling. This would look good, but it would be prohibitively expensive. This is because we won't be able to cut 5" out of the 8" roof joists. What we have to do is stall another steel of about 7.7m to support the roof, so that we could have small roof joists (just 4 x 2) between two steels where the blinds would go. That would be ridiculous, and I don't know how else we'd get blinds in the ceiling. Option 3) - Curtains We could easily fit a hidden curtain track in the ceiling (eg, silentgliss). We could put up quite thin curtains for 6 months of the year. This would be affordable. It would look good in summer if we took them down, and soften the area in winter. It would be a hassle putting them up and down, and when up they wouldn't look so good in the day when open, as even thin curtains would take up a fair bit of space when over 3.5m each side. Option 4) - We could use moveable screens. They could shield us from the sun when needed, or add some warmth in winter. One issue is that a couple of screens might look a bit puny compared to what will be very large glass doors. I've never lived with nice big glass doors before, so would love some tips from those of you who have. Many thanks

So the beads do just go all the way down to the foundations?

We're building a kitchen extension, which will take up the entire width of the house. The sides of the extension will be in brick, matching the original house. The view from the garden will be an 8m wide, 3.4m high block. Most of that will be sliding glass doors, surrounded by a goalpost shape of blocks (parapet roof, no gutters or downpipes). We could render and then paint that black, or dark grey, but I fear the colour will fade various amounts in the sun. Instead I'd like to tile it with dark grey porcelain tiles. I did see something similar in a newspaper, but I don't have a copy any more, and can't find it online. Has anyone else done or seen similar? Does anyone have any advice they could share? Many thanks

Thank you! The builders who have looked at the job so far don't have experience with this method, and I don't think my building regs guy does either. Should the cavity wall just be built as standard (obvs without insulation)? And do the beads then fill all the way to the foundations, past the DPC? It sounds like the best option for us, but I am concerned that none of us here have any experience with it. Are they any installers you could recommend?

So in order to avoid a slip plane, are there some circumstances when you do need mortar under DPM or DPC?

Hi all Well we applied for planning last November, and got rejected. Fortunately we've just won on appeal, so I'm getting the building regs drawings prepared. I'd like to know more about Graphite blown bead insulation, or EPS bonded beads (are they identical?): What are peoples good and bad experiences? Can anyone recommend a company to install them? (I'm in Brighton, if it makes a difference) Thanks :)

Ok, photos attached One just giving a general view of the wall, the other showing how it attaches to our house. The window (edge) to the right of the join will be inside our new room).

Yes, there will be one. Hopefully they'll just sign and leave it to me, as I can't afford to pay for a surveyor for them. Lol, I wish. It's a nice old wall, not a good old wall It won't have good foundations (might not have any at all) - it already leans and has cracks in it. It's just that it's over 100 years old, is a nice red colour and has character. As a garden wall, I like it. If needed, I'll do that. But we definitely can't build off of it. Knocking it down (for the length of the extension) would be good for us, I guess I should at least ask the neighbours

I expect the boundary wall is shared. Our house is the boundary as far back as our house goes, and then the 9" ish wide boundary wall starts, and that wall is half on each side. I haven't asked the neighbours about knocking it down. It's a nice old wall, I don't suppose they'd want it gone, and for half the run of my extension the boundary wall is the back wall of their potting shed, so they won't want me knocking that bit down. Without the potting shed issue, it would make some sense, as the boundary could be a simple continuation of our house. Assuming we leave the wall, the plan is to dig 1m lengths of foundation (hopefully not too deep), put some steel continuation bars in, and fill them one at a time.

We're talking about where the wall butts up against the boundary wall, so no one would be able to see it. Once the wall went above the boundary wall, the brickie would go to the neighbours side to build. Although the opinion here seems to be that we're better using brick and block anyway.

If I go with this design, the finished walls will be about 15.5". One wall is a completely new wall, so that's fine - the other wall will be joining an existing Edwardian cavity wall, which is about 11 or 12" wide. Is it ok to add PIR (maybe 75mm) to the inside of the existing wall, or will that cause problems?

Thanks. So having your 25mm of PIR was more expensive than another 25mm of cavity and beads, but it was worth it for the better uValue and ease of running cables. All sounds good. I'll suggest the architect puts this in the plans. Would I need a specialist to fill the cavity with beads? Presumably they drill holes in the finished blockwork, and once they're done I can install the PIR?

I didn't word my question well - so the uValue is better having 25mm of PIR inside (and 150mm beads filled cavity), that having a 175mm bead filled cavity - which begs the question why not make it a 125mm bead filled cavity, and have 50mm of PIR inside?

Thank you. Is the uValue increased by more than an extra inch of cavity with beads?

So there seems to be something of a consensus, suggesting I go for brick and block. Sounds good to me. I've just been reading through this thread, which looks at the insulation options for blockwork: I see you posted on the thread above, and you went for: 150mm Cavity Graphite blown bead 25mm PIR between battens Why did you add PIR on the inside, as opposed to just using more blown bead in a wider cavity? Is it better per inch, or more affordable, or did you really do it to make running cables easier? Do you get a specialist in to do the beads, once the roof is on with the cavity sealed at the top? Thanks

What do you mean by 'attach bearers into the existing walls'? Yes, if we went for brick on the outside and timber inside, we'd have steel posts from the beams to the foundations. The plan was to have about 90mm Celotex between the joists, and then another 75mm ish on the inside - so the steel columns would only have 75mm inside of them. There may only be 2 steel columns to worry about though - one each end of the main girder. Because the steel at the end of the room would be past the glass doors (there's a 500mm ish overhang). So would that be ok? Thank you for the advice, much appreciated. If we went brick and block, how would you go about insulation?

You make the eps beads sound really good. I am concerned about how well a brickie would install the insulation (my experience of this dates back a while, and they had little interest/knowledge of insulation, I expect they're better now), so beads being pumped in sounds good. What we want: Insulation - the room is going to be the most used room of the house, so I'd like it to be fairly well insulated, and I just figured I'd probably want to do more than building regs (no science there, just a hunch). I guess there's no point going crazy, as 4 metres of outside wall will be part of the original house, which won't fair so well. Cost - I can't throw tons of money at it, so I'd want most of the extra spending in upgrading the insulation to get paid back in fuel savings over the years (tough to quantify). Is the cost of using eps beads similar to the other methods? Width - block and brick with a 150mm cavity would be about 14.5" total, which would be ok. Maybe a little more, but I wouldn't want much more room space going. I assume brick and timber would allow us to have good levels of insulation without much wall thickness. The extension is at the back of the house, so it would have to be pumped down the side path, 30 metres. Thank you for the help, much appreciated.

Could you tell me more about using eps beads please? The pros and cons, and what size cavity suits its use. Same for using rockwool or Celotex - I don't know the pros and cons of each option. I haven't yet asked him about the problem of timber shrinking, as I just think he'll say it won't be a problem, but then he's not the one who has to deal with any problems if it does. We've considered brick and block, and brick and timber (both of which seem to have issues for us) - should we also consider Insulated Concrete Formwork (ICF)? Could we just install an ICF wall up against the boundary wall? Thanks

Thanks for the warning, I'll ask him. That's why I'm asking questions on here, rather than just assuming what he says will work

No But isn't a wall tie basically just a piece of metal, so wouldn't some large screw work? Understood. I can't lay bricks, I'll need someone in for that. But I've known my chippie for decades and can do studwork with him for less than bricklaying costs, so if there was a sensible brick/timber solution, I'd like to go with it, but I understand we may be better with brick/block. Our wall will be about 3.3m high, and the boundary wall is about 2m high. I was thinking of blockwork up to the height of the boundary wall, and then brick above so it looks ok for the neighbour. Well since the wall is up against the boundary, we'll have no doors or windows there. We just have to sort out the detail where the wall turns 90 degrees, and then meets the sliding glass doors. I'd not thought of filling the cavity with beads. The architect was just suggesting a 2" gap and then some Celotex, and then more on the inside too if I wanted (as he felt it would be harder to build the wall well with a large cavity (allowing for wall ties etc). I was planning on a wall thickness of 12" - could go a couple more inches for improved insulation, but I don't want to eat into the room if I don't have to. That's why we thought brick and timber would work. Thanks you for all the help, much appreciated

Thanks for the reply. Can't we build be wall, drill through the ply and into the brick, and insert wall ties? Yes it does sound easier, but I'm concerned about getting enough insulation in. Any suggestions?

I met the architect again today, and mentioned the concern of different expansion rates if we go timber on the inside, with brick/block on the outside, and he said it wasn't a problem, and was common these days. If we do go that route, my main concern it being able to build a brick/block wall up to an existing brick boundary wall, and at the same time building a timber wall on the inside, and joining the two with wall ties: There would only be a 50mm cavity between the bricks and the Tyvek/ply/studs, which means we'd need to build the stud wall first, then put 600mm strips of ply in place (with rolls of Tyvek in the way), then reach over to lay the bricks and add ties, before doing the next strip of ply. Meaning just 6" space between the ply and the existing brick boundary wall, to get fixings in (from ply to timber stud). I wondered if instead we could build the brick block wall up to 7 feet (matching the boundary wall), and then build the timber studs with ply and Tyvek, flat on the ground, then stand it up and then add wall ties, drilling them in to the finished brick/block wall? I don't know if that's an acceptable method or not. Perhaps it would be good if the outer skin were concrete blocks, meaning we'd likely get a good fixing? Any ideas? Thanks

It's currently a typical Victorian/Edwardian house, where the kitchen extends into the garden, but not at the full house width, giving you a side return. We want to knock down the existing kitchen walls (rear wall, as side wall), and extend into the side return, and also further into the garden (there is currently a conservatory into the garden, but for the sake of understanding the plans, we can ignore that). Quicker and cheaper sounds great to me So you mean steels with a cross section of 254x146x43, and putting timber joists between them? That would be fine at the back of the extension, but we'd still need something big to support the existing first floor and roof (a 320kg steel sounds reasonable, I was concerned it would be more). I'm hoping we'll be ok with flat ceilings. The existing kitchen ceiling is around 3.15 / 3.2m high, and we're after a finished ceiling of 2.76m, so there should be room for the steel. Thank you for the help

Thanks. I mentioned to the architect that I want to exceed the building regs insulation requirements, so that the room stays warm with little heating, so he suggested timber studwork inside the bricks. How do you think we could improve the insulation if we go brick and block? Are posi-joists the zig-zag timber/metal beams? We were thinking of a large steel universal beam across the width of the kitchen, supporting the room above. Getting it in, almost by hand, will be a challenge. One option is to have it in 4 pieces - instead of one length of 8m (ish), a 5m & 3m piece joined together, running parallel with and attached to a similar pair, 3m & 5m, so the joins don't overlap. This is pure guesswork at this stage, as the architect won't know until he asks his engineer. Then a steel from that back towards the house, to support the side wall of the room above. If that can't be done, we'll have to have a supporting steel column part way along the length. Then we'd also need an 8m ish steel over the sliding glass doors. And possibly a third too (one issue I have is allowing for roller blinds fitting into the ceiling). Then we'd just have standard timber joists between the steels. The long posi-joists are something I've seen on tv, and plan to ask the architect about, in case we can use them (as well as some steel, which is unavoidable).