DIY Attic Insulation

McGilla

Hi all,
Just a bought a 30 year old house, so I've a feeling I'll be in this section from now now on.

I am looking at re-insulating my attic as the fibre glass layer is very thin, patchy and seems very old.

We have a 98 sp M home, and I'm wondering would it be cheaper to get a company in, or to do it myself?

I work out for 90 sq meters i will be looking at paying €350+ for materials in Woodies, would I be better off just getting a contractor, as they seem to be charging €400...

Any advice, tips or recommendations are much appreciated.

homer911

For a start, I would not be looking to buy the materials in Woodies - you will get much cheaper from your local Builder's Providers or even B&Q

Secondly, are the quotes directly comparable? What depth of insulation and what U values are you comparing?

McGilla

homer911 wrote: »

For a start, I would not be looking to buy the materials in Woodies - you will get much cheaper from your local Builder's Providers or even B&Q

Secondly, are the quotes directly comparable? What depth of insulation and what U values are you comparing?

Woodies was just my first port of call, didn't even consider others so thanks, will look into cheaper supplier.

The quote of in and around €400 was taken from another thread on here, not an actual quote for my hoem. I have to get one done later ion the week.

id like to know in other peoples experiences is it worth doing it yourself, to save some cash.

Also would you have any recommendations on which grade fibre glass to use?

Thanks a mil,

mloc123

90sqm home, is it a bungalow...? Is you attic space 90sqm? or 45?

McGilla

mloc123 wrote: »

90sqm home, is it a bungalow...? Is you attic space 90sqm? or 45?

Spot on, its a bungalow.
Actually after thinking about it, attic space is probably 70 m2 after considering a flat roof extension has no attic, and also there are a number of skylights.

slimjimmc

I assume you're talking about insulating the attic floor, not the roof slopes (in which case the skylights are irrelevant to the job except for lighting).

Insulating the attic with roll insulation is relatively easy but can be physically taxing, you have to be able to spend time on your knees or crouching on your honkers, getting up and down just to move about the attic. Being wrapped up from head to toe in a boiler suit or similar covering can make it hot sweaty job too. If you're reasonably agile then it can be an easy DIY job.

McGilla

slimjimmc wrote: »

I assume you're talking about insulating the attic floor, not the roof slopes (in which case the skylights are irrelevant to the job except for lighting).

Insulating the attic with roll insulation is relatively easy but can be physically taxing, you have to be able to spend time on your knees or crouching on your honkers, getting up and down just to move about the attic. If you're reasonably agile then it can be an easy DIY job.

Yes, I'm looking at doing the attic floor. ( i might do the roof slopes too, will only add to the effets anyway.

I am well able to do it, that's no issue, Im just wondering if ill save much or if it is just as cheap to get a fitter to do it.

I dont want to spend a weekend up in the attic covered in fibre glass to find out i've saved €50...

mloc123

McGilla wrote: »

Yes, I'm looking at doing the attic floor. ( i might do the roof slopes too, will only add to the effets anyway.

I am well able to do it, that's no issue, Im just wondering if ill save much or if it is just as cheap to get a fitter to do it.

I dont want to spend a weekend up in the attic covered in fibre glass to find out i've saved €50...

I can't see how a company would do it for 400e.

You can get 5m2 of rockwool 150mm for about 26e... materials alone will cost you about 400e

You could but 100mm for less, and you could buy cheaper quality again for maybe 20e for 8m2.

slimjimmc

It'll be cheaper to DIY. You can do the job at your own pace over a few evenings.

Apparently there's not much to be gained financially by insulating the roof slopes unless you plan on converting the attic for habitation. Most of the heat savings are gained from beefing up the ceiling insulation. I believe at least 300mm is the current standard.

McGilla

slimjimmc wrote: »

It'll be cheaper to DIY. You can do the job at your own pace over a few evenings.

Apparently there's not much to be gained financially by insulating the roof slopes unless you plan on converting the attic for habitation. Most of the heat savings are gained from beefing up the ceiling insulation. I believe at least 300mm is the current standard.

Thanks!

irelandspurs

https://www.build4less.ie/index.php?cPath=946_685_889 good site price wise,but go to a few places get written quote then go to next hardware price then show them best quote you got and ask will they beat it.

NobodyImportant

Yes, DIY is going to save you.

Earthwool in the likes of Chadwicks. Good U value and not half as itchy as most stuff. Rockwool is pretty itchy, its more expensive, but it also dampens sound levels if you want that as an added bonus.

Get a boiler suit, put on old clothes (that you can bin afterwards), mask, eye mask (i got this stuff in my eye, its horrid), and get to work. 300mm on the ceilings. Will make a big differences.

The skylights, what insulation is behind the plasterboard running to the light on the attic side? Ours were uninsulated. I bought slabs of 1 inch polystyrene, cut them to fit and stuck them on the back of the plasterboard with expanding foam and also used that to seal the gaps. It should provide a relatively cheap alternative to xtratherm boards.

Johny 8

272 for 200mm earth wool
416 for 300mm earthwool
+ 220 for labour.

slowburner

I insulated my 80m2 attic space in two half days, to a thickness of 300mm, for €200.
I can't remember the name of the material, but it is much more pleasant to work with than glass wool. No itching, rashes, or coughing fits.

BTW, what is the thinking on laying insulation over the likes of electrical junction boxes, light fittings etc.?

landcrzr

Just a note on where you put your insulation.
Insulating at ceiling level means you are heating the space you use most, ie not your attic. Putting insulation against your roof felt , ie on the slope, can be a bad thing for a number of reasons.

You are now paying to heat your attic that you probably never use.

Most roof spaces are supposed to have air moving through them, not a wind but reasonable ventilation. This is necessary as your roof slates/tiles will get condensation forming on the inside otherwise. Part of the reason you have felt under the slates is to prevent this condensation dripping into your attic. Modern felts are breathable to allow some air through for this reason also.
If you insulate the rafters and no provision is made for ventilation you can create a stagnant damp environment for the battens and rafter tops, perfect for rot. It is called interstitial condensation. Also if the insulation gets damp due to this, it is effectively useless and will conduct heat.

Of course it is possible to insulate at rafter level correctly, but it is difficult to do so when retrofitting, and even more difficult getting someone to do it right.

My advice, keep it simple and insulate just above your ceiling, it will be cheaper (less surface area) and easier to fit.

McGilla

Hi all,
Project complete.
I've insulated the entire attic floor with 200mm fibre glass wool from Woodies.
I shopped around and Woodies had a sales, and were cheapest for exact same product as else where.
Attic is 80m2 (est) it took my 8 roles at €32 per roll - €256
I managed to get is all done in one day, and noticed instant improvement the next day when waking up.

Attic is no freezing when i go up, (always a good sign)

Also I insulated the trapdoor with silver foil kingspan, and replaced trap-door seals.

Thanks for all the advice.

paddy147

A few pics to stimulate the mind.


Oh and Woodies....are a RIPP OFF.A good decent builders providers will sell you 200mm Knauf for around 18-20 euro.