Does my roof need insulation?

Roen

Hi,

Just wondering would it be an idea to insulate the roof in my house?

I recently moved into a 2006 built C2 rated bungalow. The attic insulation in general could use a bit of TLC I reckon. It's 10 years old now and is compressed in some places and pushed aside in others so that you can see the ceiling slab below.

The attic has been converted into a bar and pool room area (Hurray!). The inner area is insulated with 100mm foil backed solid insulation. But the roof outside that area in the storage area is not insulated at all.

Looking down the long side. You can see the 100mm foil backed insulation facing in to the inner area. 200mm insulation between the joists.




The roof is uninsulated as far as the inner attic area. Just the damp proof membrane (I think).




The part of the roof that covers the inner area is insulated with more of the 100mm solid foil backed insulation. Looking up the angle above the inner area.




Joist depth is approx 210mm, which fits with what the owner said about him using 9x2" joists.
Joist spacing is 360mm
Rafter depth is 145mm

So I guess my questions are; Should I insulate the uninsulated section of the roof and should I cover the existing insulation with 100mm more of insulation rolled across the joists perpendicularly to the existing stuff?

Any input appreciated!
R.

punisher5112

Do no harm can never be too much really.

Roen

Cheers,

So is that both the roof and the floor?

punisher5112

Really depends what your happy spending.

punisher5112

While at it cover the tank as it looks exposed if insulation is above should be OK. What you have done already is good but be careful of cables and if down lighters are installed below.

Roen

punisher5112 wrote: »

Really depends what your happy spending.

That's the rub, I'd be happy to spend if there'll be a tangible benefit in terms of comfort. That comes first, saving money second.

No down lighting installed at all so that uncomplicates things a little. I thought there was no issue in covering cables though I have to say.

Covering the tank is on the list alright.

MicktheMan

Adding any insulation to the sloped roof area (between the rafters) is a complete waste of time, money and will add nothing to the comfort of the inhabitants.

Gumbo

You could beef up the insulation on the horizontal joists with some sort of insulated board that doesn't condense the existing wool insulation. Then beef up the vertical stud walls by using a similar method.

Doing the slopes within the room will be harder as my opinion is you will have to place up an insulated board on the underside of the rafters then re-skim etc

Particular attention to the junctions needs to be taken.

ted1

Is the house cold? On a frosty morning is there frost in the roof?

mickdw

Do not insulate the bare sloped section within the attic.
You roof appears to be designed so that the triangular side attic as per the photo is outside the insulated envelope and it should have external cold air freely circulating through there.
Similarly, I'm sure you have a small top attic. Again the roof slope within the top attic shouldn't be insulated with the flat portion that forms the ceiling to the first floor room should be.
Back to the side attic, you could boost what is there by running an additional 150 mm quilt across the joists.
Be sure to retain ventilation from eaves into this attic space.
As 2006 built houses go, I'd say you have got a good one insulation wise. It would be reasonably compliant with the regs of the time.

Roen

Cheers lads,

Appreciated!

bertie 56

Hi there,

I would remove the pile of sh.te you have between the ceiling joists, and redo something clean. Good steady Rookwool ( see picture ), 200 mm between the ceiling joists is plenty, and you'll be able to use the attic space .
( Tidy up the cables too, I can't believe the mess you always find in attics ! a 2006 work ? seems Middle age job...)

Roen

bertie 56 wrote: »

Hi there,

I would remove the pile of sh.te you have between the ceiling joists, and redo something clean. Good steady Rookwool ( see picture ), 200 mm between the ceiling joists is plenty, and you'll be able to use the attic space .
( Tidy up the cables too, I can't believe the mess you always find in attics ! a 2006 work ? seems Middle age job...)

Sorry bertie56. Only seeing this reply now.
Thanks for the input.
If I were to remove it what kind of cost would you be looking at for rockwool? Attic is 15m x 10m.

I've already started to clip up cables to get them above anything I lay down.

The providers here only stock fiber glass.
So I'd be looking at getting a crew in to do it.

Can you hire the blowers yourself as I'd prefer to DIY this as much as possible.
Thanks again.
R.

bertie 56

Roen wrote: »

Sorry bertie56. Only seeing this reply now.
Thanks for the input.
If I were to remove it what kind of cost would you be looking at for rockwool? Attic is 15m x 10m.

I've already started to clip up cables to get them above anything I lay down.

The providers here only stock fiber glass.
So I'd be looking at getting a crew in to do it.

Can you hire the blowers yourself as I'd prefer to DIY this as much as possible.
Thanks again.
R.

Hi there,

Quick quote here for some Rockwool flexi-slab , from one supplier only :

100 mm slab = 11.30 inc vat / m2
So 2 layers of 100 mm ( that does 200mm ) = 22.60 /m2

That's a quick quote for one bale , you might find better somewhere else, and if you buy in bulk too .
And it's a slab, no blower here, DIY stuff if you know a bit...