Dormer Insulation Question?

bonzos

Hi folks, I am looking for some insulation advice. We live a 20 year old dormer house which needs it insulation upgraded. I received 2 quotes so far, one from a national company to pump the walls with bonded bead and 300mm fibreglass in the attic/side crawl areas and another quote from a local company to again pump the walls but install spray "foam" style insulation in the side attics. Both companies quoted almost the same price however the local company are not registered for the SEAI grant. I would like to know has anyone feedback on the advantages of spray foam over fibreglass in the attics and would the lack of SEAI approval put you off the well established local company?

MicktheMan

Before wasting spending your money on pumping the walls etc, have your house tested for air tightness. Then make your decisions.

shugy

MicktheMan wrote: »

Before wasting spending your money on pumping the walls etc, have your house tested for air tightness. Then make your decisions.

Wouldn't agree! Yes get it air tested but also spend the money on pumping it.

An example, you have a 2 houses, both with 10 air leaks. You block up all air leaks in both houses and only pump the cavity and upgrade insulation in one house. What house do you think would be warmest!

Calahonda52

shugy wrote: »

Wouldn't agree! Yes get it air tested but also spend the money on pumping it.

An example, you have a 2 houses, both with 10 air leaks. You block up all air leaks in both houses and only pump the cavity and upgrade insulation in one house. What house do you think would be warmest!

Interesting that you advocate pumping when here
http://www.boards.ie/vbulletin/showthread.php?p=98341105#post98341105
you ask about pumping.
it looks like a case of
"Pump the wall with pounds of polly,
Fa la la la la la la la la.
'Tis the season to be jolly"

To start with neither of the houses will be warmest, at best one will be warmer.

What is the payback on say 20k of retro insulation work?

MicktheMan

shugy wrote: »

Wouldn't agree! Yes get it air tested but also spend the money on pumping it.

The point of testing the house is to decide how best to spend the money. Of course, if there is a limitless pot, then sure, pump away.

MicktheMan

shugy wrote: »

An example, you have a 2 houses, both with 10 air leaks. You block up all air leaks in both houses and only pump the cavity and upgrade insulation in one house. What house do you think would be warmest!

Here's another one:
2 20 year old dormer houses, 1 super insulated but no air tightness measures, the other with min insulation but good air tightness measures. I know which I would prefer.

shugy

Calahonda52 wrote: »

Interesting that you advocate pumping when here
http://www.boards.ie/vbulletin/showthread.php?p=98341105#post98341105
you ask about pumping.
it looks like a case of
"Pump the wall with pounds of polly,
Fa la la la la la la la la.
'Tis the season to be jolly"

To start with neither of the houses will be warmest, at best one will be warmer.

What is the payback on say 20k of retro insulation work?

Are you right in the head! My question is totally different. Your trying to compare apples and oranges!

shugy

MicktheMan wrote: »

Here's another one:
2 20 year old dormer houses, 1 super insulated but no air tightness measures, the other with min insulation but good air tightness measures. I know which I would prefer.

Your trying to compare them same apples and oranges!

MicktheMan

shugy wrote: »

Your trying to compare them same apples and oranges!

Maybe so, but at the end of the day its all fruit.

Apples == conductive heat loss
oranges == convective heat loss
fruit == overall heat loss

bonzos

Thanks for the feedback, I will get the house checked to see how air tight it is. However am I right in saying that most of the issues with air tightness will be due to my 20 year old windows and doors? As I am not in position to replace the windows which of the 2 methods of insulation would best help to keep the heat in my home?

893bet

shugy wrote: »

Wouldn't agree! Yes get it air tested but also spend the money on pumping it.

An example, you have a 2 houses, both with 10 air leaks. You block up all air leaks in both houses and only pump the cavity and upgrade insulation in one house. What house do you think would be warmest!

So basically you are backing up mick in saying to sort out the air leaks first?

Extra insulation will do squat of there is a lot of uncontrolled ventilation.

MicktheMan

bonzos wrote: »

1. I will get the house checked to see how air tight it is.
2. am I right in saying that most of the issues with air tightness will be due to my 20 year old windows and doors?
3. As I am not in position to replace the windows which of the 2 methods of insulation would best help to keep the heat in my home?

1. Good, make sure you are home during the test so you can appreciate what is at play.
2. Imo and from experience, no.
3. If it turns out that the primary heat loss mechanism is lack of air tightness, then this is what needs to be addressed before any insulation solution will be effective.

shugy

893bet wrote: »

So basically you are backing up mick in saying to sort out the air leaks first?

Extra insulation will do squat of there is a lot of uncontrolled ventilation.

Don't talk muck!!!!!! Even if there's air leaks, extra insulation will still be better than what the house was like without it. Yes you will still lose heat out the air leak but the house will still be warmer!

893bet

shugy wrote: »

Don't talk muck!!!!!! Even if there's air leaks, extra insulation will still be better than what the house was like without it. Yes you will still lose heat out the air leak but the house will still be warmer!

Depends on the level of air leakage. If there is a lot of draughts then the insulation will have close to zero effect.

shane b

We bought a former bungalow about 4 years ago and our heating bill the first year was quite high. We got an energy audit conducted on the house which included door blower test and thermography. Door blower test showed up all the leaks in the house and in places we didn't expect. Places like around the window frames and where plumbing pipes came through the walls/floors in larger than required holes. Well worth the money as it gave us an idea what to use our money on first.