Loft conversions - top tips from those that have done it?

[shakespearegirl]

When we did ours loft companies were extortionately expensive compared to builders. £70k vs £40k.

My advice, move out during the process! It’s really messy and noisy and we were a pain in the arse for the builders by being in the house. They were great (mostly) but trying to keep the house livable created so much extra work for them

 

[Brainaddict]

The question is not so much what kind of insulation is used, but whether it's installed properly. That means broadly:
2) Are there air gaps everywhere (if there are gaps where air can easily move from one side of the insulation to the other, you can forget it performing as it's supposed to) which comes down to how fastidiously it's installed

The problem is, what can I, the average punter, do about poor building standards (which is to say, the normal building standards in this country I'm afraid to say)? If you lean over the builders' shoulders and direct them, they hate you for it, and even want to charge extra for going above their usual standards. If you don't lean over their shoulders they do things as cheaply and quickly as possible. I admit we have to get builders at the cheaper end of the market, but it doesn't always seem to improve things to go more expensive. On the specific issue of fitting attic insulation, a friend of mine ended up sacking his builder because he wouldn't fit the insulation properly (i.e. without gaps). He ended up literally fitting it himself. And then of course had a load of grief with the builder, who couldn't understand why he had been sacked for doing things the way he had always done things.

 

[Brainaddict]

Can't seem to copy the link but it's part number 68120 from Screwfix.

Great, thanks

 

[teuchter]

Can't seem to copy the link but it's part number 68120 from Screwfix.

Multifoil. Very controversial in some quarters (real world performance nothing like that claimed).
I'd better leave this thread alone for a bit

 

[teuchter]

The problem is, what can I, the average punter, do about poor building standards (which is to say, the normal building standards in this country I'm afraid to say)? If you lean over the builders' shoulders and direct them, they hate you for it, and even want to charge extra for going above their usual standards. If you don't lean over their shoulders they do things as cheaply and quickly as possible. I admit we have to get builders at the cheaper end of the market, but it doesn't always seem to improve things to go more expensive. On the specific issue of fitting attic insulation, a friend of mine ended up sacking his builder because he wouldn't fit the insulation properly (i.e. without gaps). He ended up literally fitting it himself. And then of course had a load of grief with the builder, who couldn't understand why he had been sacked for doing things the way he had always done things.

To be honest, if budget is tight, then the most reliable way probably is to do it yourself. There are builders who will do it properly, and are genuinely invested in doing a good job, but they will charge more because they'll spend more time doing it. This is particularly true when you're retrofitting to an old building, because nothing is regular shapes and sizes... if you are doing rigid board insulation you end up cutting virtually every piece to a custom shape.

 

[teuchter]

Depends what insulation they put in. Mine was 4" fiberglass and was boiling in summer and freezing in winter.

Assuming you mean mineral wool - that's nowhere near enough and would have no hope of even meeting current minimum building regs standards.
Should be at least three times that thickness in my opinion.

 

[Brainaddict]

Assuming you mean mineral wool - that's nowhere near enough and would have no hope of even meeting current minimum building regs standards.
Should be at least three times that thickness in my opinion.

Which would take up too much space in a lot of builds where you have to keep to existing roofline. What's the best option for a conversion do you think, is it celotex/kingspan but it needs to be well fitted?

 

[teuchter]

Which would take up too much space in a lot of builds where you have to keep to existing roofline. What's the best option for a conversion do you think, is it celotex/kingspan but it needs to be well fitted?

Yes - they give best insulation per unit of thickness. Needs to be well fitted, and ideally, try and get a continuous layer inside of the rafters, because even if you fit tightly between them, the rafters themselves are bridging the layer.

Intermediate options include polystyrene - the grey stuff is better than the white stuff - and woodfibre based boards are becoming more popular - eg: Home - Pavatex

These will do better than Rockwool but not quite as good as PIR/PUR (Celotex/Kingspan). Some people are sceptical whether the values claimed by Celotex etc are quite matched by reality, and having been listening to recent Grenfell evidence, maybe they are right.

That multifoil stuff claims to give you good results for a minimal thickness but as I said earlier, a lot of this is a bit dubious.

If you're a millionaire you can try aerogel.

In all cases, do check with the manufacturers/suppliers that it's right for your particular situation though, because things can get complicated with vapour barriers, roof ventilation etc.

 

[Brainaddict]

ideally, try and get a continuous layer inside of the rafters, because even if you fit tightly between them, the rafters themselves are bridging the layer.

Thanks, I suspect a lot of cheaper conversions don't do this and I wouldn't have thought to spec it.

 

[Cloo]

First guy came today - he's going to draw us up a plan based on what neighbours have as a starting point, quote on basically replacing the damn roof, and we can work from there. Was well on top of fire/building regs (we'll have to lose glass panels in/above doors apparently, which is fine - we don't like them much & have only kept them to get some light into that hallway, which will be less necessary with the skylight) and we'll have to have mains fire alarms in all rooms. Alternative is fire doors everywhere, but you'd be supposed to keep them shut at all times - yeah, right!

He's also done work for a colleague of mine and has a big book he's left us of all his recommendations, which I'm willing to bet will include a few other people we know from round here. In theory he has space from April, but we've said July's probably our earliest start as it's after daughter's bat mitzvah (one bit of stress at a time please) - plus I think we might bugger off the my parents' place in Slovkia for 3 weeks over summer. Interestingly, like the guys down the road gsv spoke to, he said don't even try to anything that needs planning permission - Barnet planning are extremely resistant to granting. Which is fine, PD should be more than enough for our needs.

I expect most likely we'll go with him given pedigree - neighbours said he was on the pricier end but worth it. Will get another two opinions anyway for comparison, or in case another one has any interesting ideas.

 

[teuchter]

Thanks, I suspect a lot of cheaper conversions don't do this and I wouldn't have thought to spec it.

One other option is to do rockwool between the rafters and then rigid board on the underside.
If you want to get into this in detail, there are various U-value calculators online which can give you an idea of the relative benefits of putting different types/thicknesses of insulation in different parts of the buildup.

 

[WouldBe]

Assuming you mean mineral wool - that's nowhere near enough and would have no hope of even meeting current minimum building regs standards.
Should be at least three times that thickness in my opinion.

This was on the sloping roof with 4" of glass fibre insulation crammed into the 3" gap between the plasterboard and the roof felt which is why I replaced it.

 

[teuchter]

This was on the sloping roof with 4" of glass fibre insulation crammed into the 3" gap between the plasterboard and the roof felt which is why I replaced it.

Depending on exactly what the 'roofing felt' was, they shouldn't have crammed it in there like that; there should be an air gap between the insulation and the underside of the felt to stop condensation building up.

Very common to see this though.

 

[Cloo]

Have phoned loft convertors #2 who are working down our street - he's going to send me a rough quote for what we're after and then we'll talk further.

 

[weltweit]

Someone I know who had a spacious loft conversion hated the fire doors which they had been required to fit so after the final inspection he replaced them all with normal doors and put the fire doors in the garage. I hope he never has cause to regret that.

 

[Cloo]

Someone I know who had a spacious loft conversion hated the fire doors which they had been required to fit so after the final inspection he replaced them all with normal doors and put the fire doors in the garage. I hope he never has cause to regret that.

Bloke today said for a time they had to do some kind of fire door springs on all doors and often took them off at the end as they just weren't practical to live with, eg for people with small kids. The option now is fire door or mains-wired alarms everywhere, the latter obviously being cheaper.

 

[Epona]

Bloke today said for a time they had to do some kind of fire door springs on all doors and often took them off at the end as they just weren't practical to live with, eg for people with small kids. The option now is fire door or mains-wired alarms everywhere, the latter obviously being cheaper.

You can get safety guards for doors with chains - living in a flat my doors have them, the safety guards are worth it (once did my finger an injury in a door fitted with a fire-chain and no safety guards, and I am not a small kid - just clumsy)

 

[Cloo]

Got my first quote it's... on the high end, but I always knew this guy was likely to be the priciest, OTOH from all I hear he very much sticks to what he quotes. It's stretching us what with the costs of decor/finish/buying a bathroom suite but doable and may be worth it just on the ground of he comes so strongly recommended and does pretty much everything.

Be interested to see other guys' quote (incidentallu the house they're working on 10 doors down got broken into via the back fence to nick some of their gear last night )

 

[teuchter]

Got my first quote it's... on the high end, but I always knew this guy was likely to be the priciest, OTOH from all I hear he very much sticks to what he quotes. It's stretching us what with the costs of decor/finish/buying a bathroom suite but doable and may be worth it just on the ground of he comes so strongly recommended and does pretty much everything.

Be interested to see other guys' quote (incidentallu the house they're working on 10 doors down got broken into via the back fence to nick some of their gear last night )

What does the quote tell you about what you are going to get - how detailed is it?

 

[Cloo]

Pretty detailed, will be looking through it to establish and I dare say asking some questions.

He's drawn out exactly what our neighbours have so we know what the space 'feels' like. Ideally we might want a large bath space so we could get a bath and a shower unit it - question is whether we can get that with PD (it's in a dormer) or within the structure of the roof.

Both gsv and I like baths most, but would like to have a decent sized, dedicated shower unit somewhere. Another option I realised is that we could change the en-suite of our current bedroom from a short bath to a large shower, that way getting us a shower unit (our intention is to make our current bedroom a library/study type room - and, uhm, it'd have an en-suite!) I think we could convert that fairly easily, and that might be the cheaper answer than extending the loft bathroom. Or looking at the plan, maybe the loo could be pulled back into alcove taking up some of the bedroom space, but probably not, as gsv is already concerned about loo flushing at night/early in the morning!

 

[Cloo]

Here's the plan, nb he has a large shower in bathroom, but I know our neighbours have a bath on perpendicular wall in same space.

 

[WouldBe]

Here's the plan, nb he has a large shower in bathroom, but I know our neighbours have a bath on perpendicular wall in same space.

View attachment 241141

You could put the wash basin between the loo and the door then you could get a bath with a shower over it along the opposite wall.

 

[Cloo]

You could put the wash basin between the loo and the door then you could get a bath with a shower over it along the opposite wall.

Yeah, I think that might be what the neighbours have, or possibly the sink under the window. I think neighbours to our other side have a long, narrow walk-in wardrobe instead of a bathroom in their loft. Gsv asked builder if a long, narrow bathroom might be an option, but apparently something to do with floor raising means that's not a goer.

I love the idea of getting something like this built in under the eaves in a bedroom, but imagine it'd cost

 

[not-bono-ever]

we went for a massive shower , biggest we could get for the space, as it didnt proportionally cost much more for the bigger one. make sure you can get access to the shower drain from the side as it will leak- we has to cut a hole in the ceiling below to access it when it did start to leak. meh

 

[teuchter]

Pulling the loo back would likely not be possible because that room's on a half level and it would consequently eat into the ceiling of the main rooms below

 

[teuchter]

Pretty detailed, will be looking through it to establish and I dare say asking some questions.

I'm interested in whether it specifies things like type and thickness of insulation, the exact type of flat roofing sytem, the type and specification of windows, that kind of thing.

I'm interested, because in my experience these are things that homeowners often don't think much about. In some cases they simply don't really care as long as the thing stands up and doesn't leak immediately, but in some cases it's because they don't know that there are quite a few options to choose from, and that these can have quite a significant impact on the cost and on how good the end result is.

For example windows - if the quote doesn't specify what type, then you can probably assume that they are the cheapest PVC ones they can get off their preferred merchant. Sometimes people don't really realise this until they appear, and might have preferred to pay a little extra for ones that kept more heat in, or had less chunky frames and let in more light, or were easier to clean, or had a warranty they could claim on when they go wrong, or whatever.

 

[Cloo]

Thanks - I suspect this guy is fairly high-spec - as I said, he did the neighbours 10 years back and it looks pretty solid, but we can check what they used in any case. They told us they were especially pleased with the very quiet and solid floors.

Decor costs after building work are relatively low as there's no stripping and preparing and they can do a room in a day or two IIRC. We managed a fairly nice bathroom suite and tiles for about 2.5k, but if we do get a shower in I guess that's nearer 3k. If we want built in wardrobes, that'll be a few k - and I need drawers cos I like to be able to shove stuff away.

 

[teuchter]

Thanks - I suspect this guy is fairly high-spec - as I said, he did the neighbours 10 years back and it looks pretty solid, but we can check what they used in any case.

You shouldn't have to check with them - it should say in his quote.

If the quote doesn't give details then it's not a detailed quote, and you shouldn't assume anything is "high spec". It's "no spec".

 

[A380]

Pretty detailed, will be looking through it to establish and I dare say asking some questions.

He's drawn out exactly what our neighbours have so we know what the space 'feels' like. Ideally we might want a large bath space so we could get a bath and a shower unit it - question is whether we can get that with PD (it's in a dormer) or within the structure of the roof.

Both gsv and I like baths most, but would like to have a decent sized, dedicated shower unit somewhere. Another option I realised is that we could change the en-suite of our current bedroom from a short bath to a large shower, that way getting us a shower unit (our intention is to make our current bedroom a library/study type room - and, uhm, it'd have an en-suite!) I think we could convert that fairly easily, and that might be the cheaper answer than extending the loft bathroom. Or looking at the plan, maybe the loo could be pulled back into alcove taking up some of the bedroom space, but probably not, as gsv is already concerned about loo flushing at night/early in the morning!

We had a loft conversion done about 15 years ago and really please. Except we have a bath and hose shower. However, the header tank is only about a meter above the taps and so the bath fills really really slowly. Had I have known would either have gone for some kind of pump / power shower or not bothered with a bath shower.

 

[mx wcfc]

Ours was done maybe 9 years ago. It hasn't blown off yet.

I wish I'd had the money to have it brick built though, rather than a shed hung with tiles. It's fine, but it looks a bit shit from outside.

Watch the insulation going in. Check it's all a snug fit.

As with any building quote, check what is included carefully. We didn't realise that fitting the en-suite didn't include tiling the floor or walls. Unexpected extra costs are not good.
Stuff will go wrong, it will take longer than they say. Anything extra you ask them to do will be expensive.