Insulation!

[ChrisP3]

Morning all,

One of the jobs we have on the cards for the house is to sort out the current attic insulation. The attic eve's are stuff with age old glass fibre (?) insulation, which is looking pretty grim at the moment. Also the way it's been installed isn't ideal, far too much of it apparently (or perhaps just poorly installed,) resulting in the airflow in the roof area being compromised.

I want to remove the lot, including the stuff installed in the roof void and replace it, one of the main reason is the boys rooms are up there and I don't like the though of little bits of it flying around (plus one of the boys is old enough to open the door to the eve's) but also I want to try and get something a bit more efficient. Has anyone had experience of the sheep wool blend insulation, Thermafleece and the likes?

Any advice and ideas would be very welcome.

Cheers,
Chris

 

[Zebra]

Ive used Thermafleece Ecoroll between my studs. It's lovely stuff, cosy, breathable, and nice to use, (and smells vaguely of farmyards but only for a while....). Not cheap, but that's the only drawback.

 

[ChrisP3]

Thanks for the info zebra. Sorry I know I'm posting a million questions at the moment, I've just got so much to learn and I want to make sure I can do thinks as best as possible

 

[Zebra]

Oh absolutely, ask away. Three years ago when I was starting out on this project I got so much help from on here. There are bits that I absolutely wouldn't have tackled, had the kind folks on here not told me how. We're all happy to oblige if we can.

 

[Flyfisher]

Exactly. Questions are what the forum is all about. They also keep us in line and not wandering wildly off-topic . . . . well sometimes.

 

[Keithj]

I hate that glassfibre stuff with a passion! It gets everywhere, and makes me itch.

Our walls were all stuffed with wool when we had the repairs done. This was fairly grubby stuff (washed but not bleached) that I'm sure wouldn't have been suitable for the parish knitting group. It came in rolls, quite thick and relatively easy to lay. There was a lot left over, some of which I've mixed with lime putty for filling awkward cracks.

A friend of mine looked into using it to line his attic, but was put off by the price. I've no idea what price he was quoted.

 

[fryups]

Could be worth getting in touch with British Gas or similar, I have their surveyor coming round in a couple of weeks to see about them installing free loft insulation as part of gov grants etc. I think if you have already have 100mm or less, or it doesn't come above joists then you may be eligble.

 

[jocelyn plummer]

I have their surveyor coming round in a couple of weeks to see about them installing free loft insulation as part of gov grants etc.

I wonder if they will give grants on insulation material of your choice or whether they will stipulate which product you are to use :roll:

 

[Zebra]

Ha! I'd rather pay for my own insulation than have workers from government grant scheme crawling about in my loft. But I'd like to see their faces when they saw the loft hatch, which is so small a skinny person can only get through it by going arms first!

 

[MatthewC]

(Just back from hols)

I've used Thermafleece in my loft and I am very pleased with it. As said above it is expensive but it is so much nicer to work with than anything glass/modern/ticklish/itchy. Apart from being breathable, it has another major factor in its favour - if it gets wet then it dries, whereas the modern stuff becomes useless and will never dry out (in my experience).

The only thing about fitting it is that there is a knack to cutting it which is best done in compression: I laid it over a joist with a bit of batten on top which I stood on, and then it was quite easy to cut accurately.

Upstairs is always warm so I reckon it works!

 

[ChrisP3]

Thanks everyone. Some food for thought there

 

[ReidS80]

Another recommendation for thermafleece. It is a little pricey but is definitely worth it

 

[malcolm]

I've had a look at prices on the internet. Looks like Thermafleece would be around £2k for 300mm in a 100m2 loft, while the fibreglass stuff would come in under £500. Does that sound about right or are there reasonable bulk discounts available for Thermafleece from anywhere? Thermafleece would suit me better.

I found a good way to get rid of the fibreglass stuff - take it outside, spray it with water and stamp on it. Takes up very little space after that.

 

[JoceAndChris]

The difference in price you found matches what happened when we were looking. So we've only got a bit of fibre glass up there - this needs properly addressing.

I can see the appeal of sheeps wool but am reluctant to spend all that when there are 100 sheep in front of my house who need shearing. I just feel this is something I should be able to get hold of for a lot lot less than 2k!

 

[Zebra]

I worked on an eco-build project once where we looked at "making" thermafleece by buying raw fleeces for next to nothing, but treating them is a messy business! You have to wash out all the oils, or it will seep through your plaster. Then you have to dip them in a insecticide/preservative. Even doing it in an old bath in a field, in the end we didn't fancy it!

 

[LadyArowana]

I worked on an eco-build project once where we looked at "making" thermafleece by buying raw fleeces for next to nothing, but treating them is a messy business! You have to wash out all the oils, or it will seep through your plaster. Then you have to dip them in a insecticide/preservative. Even doing it in an old bath in a field, in the end we didn't fancy it!

Yes the fleece only looks nice if people have looked after their sheep more as pets rather than as a large commercial venture. The sort of people that do that often want the wool for their own spinning/ knitting to make into lovely sweaters that they sell to people who want lovely sweaters that come with a little tag telling you the name(s) of the sheep that made the wool that made the sweater ( I know :roll: )

 

[ljn]

It has been a while and it is good to see that Period Property forum is still going strong.
I have been approached by a company called Mark Group.
They have offered free loft insulation.

Background:
The building is grade II listed,
It has a double pitch roof it is a cold roof space with lots of air circulating.
There is an open box gutter that runs front to back, collecting water from the front and central valley, discharging to a hopper/drain pipe to the rear.
this means there are openings that let lots of ventilation.
The internal gutter needs keeping clear. If it gets blocked , it will overflow, flooding the building.

The installation was approved, installers arrived.
They wanted to lay 150mm insulation between the ceiling joists, then lay 250 insulation at perpendicular to the joists.
This would make the loft inaccessible for maintenance. I asked if they could just do the insulation between joists. but they said they couldn't- all or nothing.
So I sent them away.

The conservation officer said I did the rich thing. And that the green deal often is detrimental to the fabric off traditional buildings.

I spoke to Ty Mawr, and asked their advice. They have some more eco and sustainable solutions.

Is there no approved Green Deal installer that deals with heritage buildings? I would be glad to pay for the "heritage deficit" but would like to take advantage of the Green Deal without ending up with a building that can't be maintained or rotten joists…

LJN

 

[Zebra]

I would have thought that rockwool insulation was breathable up to a point, perhaps not as much as sheepswool, but breathable enough to prevent moisture getting trapped in your joists if there is reasonable airtightness in your ceilings and a good free through-flow of air in the loft.
I have used rockwool insulation in my loft (17th/18th century timber frame, not listed) in a similar pattern to that you describe, ie between the joists, and then over, and don't believe it is doing any harm to the building.
Having said that, I have no doubt that Ty Mawr's products are more eco and sustainable, that's clear.
In terms of access for maintenance, I don't think that's an argument against insulating your loft. You just have to find a way to make it accessible. The question still arises in any case, whether you go for a natural fibre insulation or a mineral fibre insulation.
I'm in people's lofts all the time in my work, and often have to step carefully over insulation laid out in the way you describe, feeling carefully for each joist as I go, and haven't fallen through yet. If your joists are more fragile, that approach might not be satisfactory.
In another loft I've used "loft legs" sold by Wickes to raise the floor level up to 350mm above the ceiling and accommodate the insulation. I've then boarded out the loft but you wouldn't have to, you could perhaps install a crawl board, raised up on timber supports, providing access only to where it is required.

 

[ljn]

The rolls of rock wool in between the joists aren't a problem, it is the 3o cm laid in the other direction that is a problem. Once laid, they say you have no idea where joists are.