Attic insulation

oleras

Folks, a quick question.

I had an insulation company out to do my house, cavity walls were pumped and that went fine.

Today the attic was insulated, I was at work so only had a look at the job an hour ago.

Basically, rolls of insulation are just laid at right angles to the joists, straight on top of each other, where there was maybe 50mm of the old glass fiber stuff from 30 years ago. Around the hatch, when you lift it back it is layered correctly, ie new stuff on top of the old between the joists and a top up at right angles, is this all the inspector looks at i wonder ?

4 bed bunglow, about 50feet long btw.

To me this seems not right, there should be no air gaps between the old stuff and the new stuff.

Is my contractor being lazy the way it was rolled out and it is up to reqs or is it just wrong ?

He is calling tomorrow to get paid.

Ill take a pic and attach it in case it sounds confusing.

Edit: cant get the pic from my phone, will do it tomorrow.

Mellor

Sounds very dodgy.
Bring the boss up to have a look. He should make them do it properly.
The boss won't want to have is company to have a bad name in your area for work like this.
So he might even knock 150 euro or so off to smooth things over.

muffler

Mellor wrote: »

Sounds very dodgy.
Bring the boss up to have a look. He should make them do it properly.
The boss won't want to have is company to have a bad name in your area for work like this.
So he might even knock 150 euro or so off to smooth things over.

Good advice indeed Mellor.

Just to add that if the works are inspected by the SEI then the contractor runs the risk of being removed from their approved list.

oleras

They called back yesterday and sorted everything out, boss man wasnt too happy with the work that was done, he had to redo most of it along with fitting about 10 extra rolls, 400mm in most places now with no air gaps.

Also got 150 knocked off to pay for a painter for the ceiling they came through, they had a plasterer out to repair it.

Very happy with the result overall, makes a hugh difference to the house retaining heat now the walls are pumped and the attic correctly insulated.

Kashkai

I'm going to redo the insulation in my attic tomorrow because despite there being two layers up there, i.e. one between the joists and one laid perpendicularly, the house loses its heat very quickly at night. The walls have 2 inch kingspan insulation in them and the windows are double glazed so I suspect the attic insulation as the culprit. I had a look last weekend and the layer between the joists is not put in well, i.e. scrunched up in places where wires criss cross, gaps left etc. This leaves sizable air pockets under the top layer.

My plan is to remove the top layer and roll out fresh insulation between the joists where needed to fill out any gaps and then lay the existing top layer back down and lay a third layer perpendicul to this (and thus parallel to the bottom layer). Is this correct or should I lay the new layer on top of the existing bottom layer and then put the last layer perpendicular? To me, this would leave air pockets were the joists run.

Any advice before the work begins?

Thanks

MicktheMan

Prosperous Dave wrote: »

I'm going to redo the insulation in my attic tomorrow because despite there being two layers up there, i.e. one between the joists and one laid perpendicularly, the house loses its heat very quickly at night. The walls have 2 inch kingspan insulation in them and the windows are double glazed so I suspect the attic insulation as the culprit. I had a look last weekend and the layer between the joists is not put in well, i.e. scrunched up in places where wires criss cross, gaps left etc. This leaves sizable air pockets under the top layer.

My plan is to remove the top layer and roll out fresh insulation between the joists where needed to fill out any gaps and then lay the existing top layer back down and lay a third layer perpendicul to this (and thus parallel to the bottom layer). Is this correct or should I lay the new layer on top of the existing bottom layer and then put the last layer perpendicular? To me, this would leave air pockets were the joists run.

Any advice before the work begins?

Thanks

Dave,
fibre insulation should not be compressed as it is the trapped air which acts as the insulant and not the fibre. So if the bottom layer is not installed correctly, then yes you need to lift and re-do it leaving no gaps and not compressing it. Here is is important to match the joist dept with insulation thickness. Mahe sure you dont compromise the roof ventilation channels at the eves. Further layers to be installed over the joists perpendicular to previous layer with no gaps.

As regards you attic insulation being the "culprit" of heatloss, don't underestimate the effect of airtightness (or lack of) on the heatloss of your house. Have you ever had an airtightness tests done?

Kashkai

MicktheMan wrote: »

Dave,
fibre insulation should not be compressed as it is the trapped air which acts as the insulant and not the fibre. So if the bottom layer is not installed correctly, then yes you need to lift and re-do it leaving no gaps and not compressing it. Here is is important to match the joist dept with insulation thickness. Mahe sure you dont compromise the roof ventilation channels at the eves. Further layers to be installed over the joists perpendicular to previous layer with no gaps.

As regards you attic insulation being the "culprit" of heatloss, don't underestimate the effect of airtightness (or lack of) on the heatloss of your house. Have you ever had an airtightness tests done?

Cheers Mick.

Yes I'll leave the vents in teh soffit clear of insulation to allow air to pass through the attic and remove any moisture.

I haven't had an airtightness test done tbh but I will seal around the light socket with mastic to eliminate any holes.

molard

oleras wrote: »

Folks, a quick question.

I had an insulation company out to do my house, cavity walls were pumped and that went fine.

Today the attic was insulated, I was at work so only had a look at the job an hour ago.

Basically, rolls of insulation are just laid at right angles to the joists, straight on top of each other, where there was maybe 50mm of the old glass fiber stuff from 30 years ago. Around the hatch, when you lift it back it is layered correctly, ie new stuff on top of the old between the joists and a top up at right angles, is this all the inspector looks at i wonder ?

4 bed bunglow, about 50feet long btw.

To me this seems not right, there should be no air gaps between the old stuff and the new stuff.
E
Is my contractor being lazy the way it was rolled out and it is up to reqs or is it just wrong ?

He is calling tomorrow to get paid.

Ill take a pic and attach it in case it sounds confusing.

Edit: cant get the pic from my phone, will do it tomorrow.

I have a house same size.how much did it cost u get the job done

oleras

molard wrote: »

I have a house same size.how much did it cost u get the job done

Attic and walls pumped plus BER cert was quoated 1600, then you have -600 for the grant. lots of dodgy people out there,get a few prices and go on friends recommendations.

1K for a warmer house, would have paid twice that to be honest !

foreman

folks, I have 2 layers of insulation. 100mm in the 80s and a further 300 last year. i need to install 4 down lighters.. Is it om to disturb the insulation while the job is being done!!

BryanF

foreman wrote: »

folks, I have 2 layers of insulation. 100mm in the 80s and a further 300 last year. i need to install 4 down lighters.. Is it om to disturb the insulation while the job is being done!!

ye of course maybe wear a mask, get yourself some down-light backing covers and consider their air-tightness also + ensure the wires are appropriately insulated where in contact with the insulation

Kashkai

I put down two extra layers of insulation (after I relaid the existing insulation that was installed by my builder very poorly) last Saturday over my bedroom which is at the end of our bungalow. Our room, which was bloody cold at the best of times, is now toasty warm. Last night I woke up at 1.30am and had to throw the duvet off me as I was too warm despite the fact that it was just 2 degrees outside. Must get round to re-doing the insulation in the rest of the attic as I find that the rest of the house feels cold now compared to my bedroom that finally feels warm:D. Money well spent:)

Smithers1

Hey My First Post!
I'm about to start insulating my own attic - 50m2. Have been looking online at best value place to get rolls of insulation. Anyone any recommendations - looks about 25Euro for average insulation roll pack. Appreciate any thoughts or views.:)

oleras

Smithers1 wrote: »

Hey My First Post!
I'm about to start insulating my own attic - 50m2. Have been looking online at best value place to get rolls of insulation. Anyone any recommendations - looks about 25Euro for average insulation roll pack. Appreciate any thoughts or views.:)

Compare U value on the rolls per m2 and get the best value if you are doing it yourself, B and Q usually have a 3 for 2/ 2 for 1 deal. Put in more than you think you need, wont be wasted.

Radiotower

I done my parents house before xmas - 110m2 bungalow. Myself and a young lad fr om across the road - 9am - 7.30pm - felt like I done 1000 sit-ups the next day... Firstly had to cut the old ins which was rolled across the joists (wool bridging), then unpack the eaves to allow ventilation, then bring ins between joists to top of timber level. Finally rolled 200mm perpenticularly across the joists. I also insulated all the pipes in the attic including overflow pipes and the small and large cold water tank.

B&Q had 3 for 2 at 24.95 per roll (5.5m2) but our local hardware store had the same rolls for 17.00 so wasn't worth travelling the extra dist for that saving although i did get the insulated loft boards for 7.00.

Really made a difference to the house already even if the weather hasn't been particularly cold since i finished it.

Smithers1

Radiotower wrote: »

I done my parents house before xmas - 110m2 bungalow. Myself and a young lad fr om across the road - 9am - 7.30pm - felt like I done 1000 sit-ups the next day... Firstly had to cut the old ins which was rolled across the joists (wool bridging), then unpack the eaves to allow ventilation, then bring ins between joists to top of timber level. Finally rolled 200mm perpenticularly across the joists. I also insulated all the pipes in the attic including overflow pipes and the small and large cold water tank.

B&Q had 3 for 2 at 24.95 per roll (5.5m2) but our local hardware store had the same rolls for 17.00 so wasn't worth travelling the extra dist for that saving although i did get the insulated loft boards for 7.00.

Really made a difference to the house already even if the weather hasn't been particularly cold since i finished it.

e

Smithers1

Thanks for that.funny the things you notice doing these Jobs. My rafters are quite shallow and although the insulation is old it comes to the top of the rafters so i will probably just cross insulate with thickest available. Incidentally another Poster put me on to The Insulation Store who have competitively priced rolls of insulation.

Roseyland

Hi folks, I have had a company insulate my attic in a new build. Basically the joists are 9" deep. The minimum requirement according to my engineer is 300mm of insulation, the company installed the 300mm but compressed it to the 9" (approx 220mm) between the joists.
I was of the thought that the insulation should go both between the joists and then perpendicular to the joists across first layer.
Any opinions on this would be appreciated!
Thanks

muffler

Roseyland wrote: »

I was of the thought that the insulation should go both between the joists and then perpendicular to the joists across first layer.

And you would be correct. Did they give you any explanation why they did this or were they asked to do it as flooring may be going down?

Mellor

Compressing 300mm down to 9" (225mm) would perform worse (thermally), than if they simply put in 9" uncompressed.

Roseyland

The insulation company tells me that the reason they only filled between the joists is that there would be a gap between each layer of 3 inches. The engineer is insisting that they are layed perpendicular to one another, he will not certify as it is. What's my best option here? Insulation company offered to lift second layer and lie across joists. Would it be better to just get more and lie over existing 2 layers?

sydthebeat

Roseyland wrote: »

The insulation company tells me that the reason they only filled between the joists is that there would be a gap between each layer of 3 inches. The engineer is insisting that they are layed perpendicular to one another, he will not certify as it is. What's my best option here? Insulation company offered to lift second layer and lie across joists. Would it be better to just get more and lie over existing 2 layers?

if they will do this for no charge, then yes... this is the best option.

both moy and knauf do a 200mm roll (8") so theres no excuse for using 2 x 150mm (6") rolls and not laying perpendicular.

Roseyland

sydthebeat wrote: »

if they will do this for no charge, then yes... this is the best option.

both moy and knauf do a 200mm roll (8") so theres no excuse for using 2 x 150mm (6") rolls and not laying perpendicular.

The problem is that the quotation i got was for 300mm, and that's what they installed.
I'm afraid that they are going to charge me for an additional layer over the existing layers.
If they were to lift the second layer and lie perpendicular, would the 2 x 150mm layers with a 75mm gap between each be adequate?

muffler

Roseyland wrote: »

The problem is that the quotation i got was for 300mm, and that's what they installed.

But not properly installed. You contact them and you tell them that you want the 300mm laid as it should have been laid from the outset.

Its their problem so let them sort it and at their cost.

sydthebeat

Roseyland wrote: »

The problem is that the quotation i got was for 300mm, and that's what they installed.
I'm afraid that they are going to charge me for an additional layer over the existing layers.
If they were to lift the second layer and lie perpendicular, would the 2 x 150mm layers with a 75mm gap between each be adequate?

technically, no, they actually only installed 9".... they may have quoted for and supplied 12~" but they installed it incorrectly and only at 9" depth.
And as has been said already, what they have installed will actually perfoprm worse than a proper 9" installation, because its the air pockets which insulate,, not the fibre. they have squashed more material into this 9" than there should be.

their installation was wrong, simple as.

These are supposed to be the educated and trained installers. At the end of the day, if your engineer isnt going to sign it off ... they are not going to get paid. Do not be hostage to shabby workmanship.
You are paying for 300mm so demand 300mm.

if they have a problem let them remove the insulation and you can get someone else to do it properly.

personally i wouldnt accept 6" between the 9" joists with 6" over because the 6" will sage down the 3" gap and pull down that section which is over each joist.

muffler

sydthebeat wrote: »

personally i wouldnt accept 6" between the 9" joists with 6" over because the 6" will sage down the 3" gap and pull down that section which is over each joist.

Aye, and with a little care the top layer can laid perpendicular and "massaged" into place up and over the joists. Might take a metre more in length but its a lot cheaper for the company to do it that way.

muffler

Roseyland wrote: »

Hi folks, I have had a company insulate my attic in a new build. Basically the joists are 9" deep. The minimum requirement according to my engineer is 300mm of insulation, the company installed the 300mm but compressed it to the 9" (approx 220mm) between the joists.
I was of the thought that the insulation should go both between the joists and then perpendicular to the joists across first layer.
Any opinions on this would be appreciated!
Thanks

Any update on this?

Roseyland

muffler wrote: »

Roseyland wrote: »

Hi folks, I have had a company insulate my attic in a new build. Basically the joists are 9" deep. The minimum requirement according to my engineer is 300mm of insulation, the company installed the 300mm but compressed it to the 9" (approx 220mm) between the joists.
I was of the thought that the insulation should go both between the joists and then perpendicular to the joists across first layer.
Any opinions on this would be appreciated!
Thanks

Any update on this?

Hi, I decided to go with and additional 150mm on top of what's already there. Insulation company offered to take up second layer and lie across joists. To add another layer they were charging almost double the cost of buying the materials alone. I bought the insulation for 300 euro and put it down myself, they had all the hard work done with the cutting! Thanks for the advice.

hbonbr

Hi, I have read lots about upgrading insulation, but is it then possible to floor over it, assuming the insulation is now 4 inches over the joists?

Any help would be appreciated.

sydthebeat

hbonbr wrote: »

Hi, I have read lots about upgrading insulation, but is it then possible to floor over it, assuming the insulation is now 4 inches over the joists?

Any help would be appreciated.

You need to increase the joist depth by adding another 4 inch timber over, preferably perpendicular to the existing

Browndog82

oleras wrote: »

Folks, a quick question.

I had an insulation company out to do my house, cavity walls were pumped and that went fine.

Today the attic was insulated, I was at work so only had a look at the job an hour ago.

Basically, rolls of insulation are just laid at right angles to the joists, straight on top of each other, where there was maybe 50mm of the old glass fiber stuff from 30 years ago. Around the hatch, when you lift it back it is layered correctly, ie new stuff on top of the old between the joists and a top up at right angles, is this all the inspector looks at i wonder ?

4 bed bunglow, about 50feet long btw.

To me this seems not right, there should be no air gaps between the old stuff and the new stuff.

Is my contractor being lazy the way it was rolled out and it is up to reqs or is it just wrong ?

He is calling tomorrow to get paid.

Ill take a pic and attach it in case it sounds confusing.

Edit: cant get the pic from my phone, will do it tomorrow.

Hi Had the exact same done in my house recently Thought it wasn't right at the time but paid up. They're looking to call out now to finalize the grant part worth €500 which they agreed to forgo ...sort of a selling point Zion guess. After seeing your post Im raging with them And MYSELF !!! They were there from 9 to 2 and It cost me 1200 for a 2500 dormer bungalow which seemed reasonable as I got other quotes .

Will post a pick in the morning just to make sure !!!

Narrator

Hey folks,

I just thought I'd post here instead of starting a new thread.

I recently took on the task of insulating my house (105 metres squared Bungalow), the existing insulation was there since the 80's and was only about 50-90mm depth across.
I laid the new insulation (20x Knauf 200mm Ekoroll) at a right angle from the joists covering over the old stuff but I don't really notice the difference in the house or it's not overwhelming me with a difference at least.

Does the insulation need time to settle? Is there something I've done wrong?
I really hope not seeing as the whole attic is done.

Browndog82

Hi Narrator,

The new insulation should be layed directly over the old stuff and thus there is no gaps. I had the walls pumped at the same time so I cant really advise of the difference with just insulation but with both done the difference is unbelievable.. In previous years having the heating on all day would just take the bite out of the cold( which was quite depressing when the heating was on all day long) but now the room is toasty warm.

Added to that I have the cut the time the heating is on by half at least if not more. The best investment I have made!!

Hope this helps somewhat

BryanF

Narrator wrote: »

Hey folks,

I just thought I'd post here instead of starting a new thread.

I recently took on the task of insulating my house (105 metres squared), the existing insulation was there since the 80's and was only about 50-90mm depth across.
I laid the new insulation (20x Knauf 200mm Ekoroll) at a right angle from the joists covering over the old stuff but I don't really notice the difference in the house or it's not overwhelming me with a difference at least.

Does the insulation need time to settle? Is there something I've done wrong?
I really hope not seeing as the whole attic is done.

is your house drafty? (air-tightness is not improved by increased insulation) so you could have improved the internal surface temp of the ceilings but there could still be way to many uncontrolled air-changes (please do not confuse air-tightness with the requirement for background ventilation)

Narrator

BryanF wrote: »

is your house drafty? (air-tightness is not improved by increased insulation) so you could have improved the internal surface temp of the ceilings but there could still be way to many uncontrolled air-changes (please do not confuse air-tightness with the requirement for background ventilation)

Thanks for the replys guys.


The house has an open plan sitting/dining/kitchen and can feel drafty or like cold is settling into the room somehow.
I have thermal curtains on the windows and draft excluders at the doors, i even went around with lighter checking for any drafts too.

the house is a bungalow and was built in the late 70's.
The windows are single glazed but i've most of them covered with the weather seal plastic sheet wraps you stick over and shrink with a hairdryer, plus the thermal curtain linings too.

I'm half thinking now should i go back into the attic and change back to go between the joists? ugh.

Handsandtools

oleras wrote: »

Folks, a quick question.

I had an insulation company out to do my house, cavity walls were pumped and that went fine.

Today the attic was insulated, I was at work so only had a look at the job an hour ago.

Basically, rolls of insulation are just laid at right angles to the joists, straight on top of each other, where there was maybe 50mm of the old glass fiber stuff from 30 years ago. Around the hatch, when you lift it back it is layered correctly, ie new stuff on top of the old between the joists and a top up at right angles, is this all the inspector looks at i wonder ?

4 bed bunglow, about 50feet long btw.

To me this seems not right, there should be no air gaps between the old stuff and the new stuff.

Is my contractor being lazy the way it was rolled out and it is up to reqs or is it just wrong ?

He is calling tomorrow to get paid.

Ill take a pic and attach it in case it sounds confusing.

Edit: cant get the pic from my phone, will do it tomorrow.

The way insulation works is same as double or triple glaze windows. Air gaps make insulation work, if You squeeze it, it won't work, because there will be no air between layers. Air gaps give more insulation, because the materials didn't touch and heat can't move quick from one layer to other and slows heat loss.

Handsandtools

Narrator wrote: »

Hey folks,

I just thought I'd post here instead of starting a new thread.

I recently took on the task of insulating my house (105 metres squared Bungalow), the existing insulation was there since the 80's and was only about 50-90mm depth across.
I laid the new insulation (20x Knauf 200mm Ekoroll) at a right angle from the joists covering over the old stuff but I don't really notice the difference in the house or it's not overwhelming me with a difference at least.

Does the insulation need time to settle? Is there something I've done wrong?
I really hope not seeing as the whole attic is done.

When insulation settle it loses it's quality.
You have to make sure all attic is covered, especially where, the winds can blow in and under it, all corners and no gaps.
I recommend using vapor barrier it will eliminate possible condensation in the insulation and possible mold, because when hot and humid air from the rooms (especially kitchen and bathrooms) gets true ceiling slab and in to the insulation when it reaches condensation point it will become wet and instead of air between the layers of insulation material you will have water what not only reduces quality of your insulation but also damages it and makes good ground for mold, because there's no ventilation inside of insulation.