Loft Insulation, is it worth it?

[compact]

Hi
Bought an old Terrace 1 yr ago. Just thinking about Loft Insulation
Hoping to sell in 1 yr (aren't we all).

Is it worth putting in Loft Insulation, at the moment we have virtually none, probably put in back in 1920's.

1) Is it cost effective over 1 yr for heat saved and those HIPS?

2) Is putting the reflective sheets behind radiators worth it?


I know I sound like a cheapskate, but the plan is to sell in 1 yr and go travelling so have to think about value adding etc.

 

[2scoops0406]

plan is to sell in 1 yr and go travelling so have to think about value adding etc.

You lost the value of any insulation you'd planned, last week.

 

[JohnD]

I once had a 1920's terraced house with no loft insulation.

In cold weather it was impossible to get the bedrooms warm, even with a 3kW fan heater running continuously. the heat loss was greater than the heaters could deliver.

With loft insulation, the rooms became warm and the cost of heating dropped like a stone.

An uninsulated home is insane.

 

[breezer]

dont bother with the tinfoil behind the rads, it allows dmp in the walls, but do go for loft insulation.

try this:

walk round the house with a baseball cap on for a day.

then take it off, feels cooler, now tell me loft insulation doesnt work

 

[PerryOne]

There is no doubt that loft insulation makes a home more pleasant to live in.
It also saves money on heating.
However, the cost of doing it to a high standard, will not be recovered in one year. On the other hand, you will not be able to sell in a year as by then the market crash will have halved the value of your home.
So, keeping in mind that it will not return to the value that you paid for it under five years - then yes.
When you do it, use sprayed polyurethane foam. This will give you maximum benefit for your money. The important thing about loft insulation is to make it a tight fit, all other types of insulation cannot do this. Foam will find its way into every space, spaces mean heat loss. All holes must be filled.
An added benefit of foam is that you can pile things into the loft without degrading the insulation.
Perry

 

[breezer]

dont touch spray foam loft insulation with a barge pole

clicky

 

[PerryOne]

Breezer, I did not write, spray under the tiles or slates.
But, between the joists over the plaster board ceiling.
Please write and advise everyone, why you think/know this is wrong.
Perry

 

[Thermo]

erm, airflow into and out of the loft?

 

[PerryOne]

Thermo, please explain?

 

[Thermo]

a loft needs airflow in and out of it to prevent the build up of moisture and subsequent rotting of the timbers. Spray foam is notorious for sealing the loft space airtight and preventing the flow of air, leading to problems later on.

 

[PerryOne]

As I wrote earlier, spray the foam between the joists.
That is to say, not under the tiles or slates (see Welsh Brickie and his problem) nor blocking the eves.
Thanks for the comment.
As a matter of fact, most damage to the woodwork in lofts is due to the water vapour rising from the inside of the house, through the plaster board ceiling which is transparent to water vapour and through and round the trapdoor into the loft. Sprayed polyurethane foam is more or less water proof and ******* the transit of water vapour into the loft.
Of course, the job done properly, would have the plasterboard removed, a almost water vapour membrane fitted, then two inches of polystyrene or similar placed under, before replacing plaster board and skim coating.
Perry

 

[freddiemercurystwin]

As I wrote earlier, spray the foam between the joists.
That is to say, not under the tiles or slates (see Welsh Brickie and his problem) nor blocking the eves.
Thanks for the comment.
As a matter of fact, most damage to the woodwork in lofts is due to the water vapour rising from the inside of the house, through the plaster board ceiling which is transparent to water vapour and through and round the trapdoor into the loft. Sprayed polyurethane foam is more or less water proof and ******* the transit of water vapour into the loft.
Of course, the job done properly, would have the plasterboard removed, a almost water vapour membrane fitted, then two inches of polystyrene or similar placed under, before replacing plaster board and skim coating.
Perry

Perry, do you work for an expandable foam company?

 

[str]

what depth of insulation (foam rolled) should you stop at? ie whats the optimum depth?

 

[JohnD]

With each additional layer, you get diminishing returns.

E.g. (figures made up for simplicity)

If you have no insulation, and lose 10kW of heat:

You add 50mm of insulation and it halves it. So now you lose 5kW of heat.

You add another 50mm and it halves the loss again. So it halves the 5kW loss to 2.5kW

You add another 50mm and it halves the existing loss from 2.5kW to 1.25kW

So you can see that although each layer costs you the same, each additional layer brings less and less benefit. But the effort of laying it is the same as well, so you may as well put down a good thick layer as it is no more work than putting down a thin one.

I am quite happy with 150mm of insulation plus boarding in my own house, but the latest standard is 250mm (ten inches). By that time the heat loss is so slight that there is no point in spending any more in making it thicker. In my case it would be a lot of work to add more and I am too lazy.

It is best to run the layers in alternate directions, so that any gaps in one layer will be covered up by the next. When you have thick insulation you nneed to look at gaps, cracks, openings for pipes and cables that let warm air escape, because they will now be the bigger sources of heat loss.

Also the next job is to get the cavity walls done (if you have them) as this is not very expensive and makes a huge difference because walls are such a large area of your house

 

[compact]

Cheers for the tips

Will get cracking on the weekend.