insulation costs

joanene

Hi, we are getting all our costs together at the moment for building our house and hope to get started soon.
Getting prices together for our mortgage is proving a very lengthy process!
We are still waiting on insulation quotes.

What should we be expecting the costs to be? ballpark figure..

Building a 2500sq ft house.
Planning to go with 150mm cavity with pumped full filled bonded bead and possibly dry lining.

For the sloped roof section we are thinking of kingspan followed by an insultaion board.

We not sure what costs to expect

Left Field

I'm afraid I cannot help you with insulation costs - however in relation to the cavity and drylining you should be careful of the following;

Any cavity over 100mm needs to be designed by an engineer. There are plenty of people out there building wider cavities regardless but as the cavity gets wider it does need specialist design.

Also make sure a condensation risk analysis is carried out if you plan on dry-lining. Sandwiching elements of structure between two layers of insulation always makes me uneasy!

Have you considered external render?

Best of Luck
Left Field

FergusD

As far as I know, 150mm is the cavity limit without structural engineering design and I've just done that, so I hope I'm right!

On the insulation front, have a look at the kingspan TW range instead of their K range. This uses a cheaper board, so if you sacrafice a little space you may end up with the same u-value for less money. Xtratherm also do similar boards (which we went with). It's probably worth your while engaging an energy assessor to advise on this type of thing, unless you're going to do a lot of reading - that said I regret having spent as money on the report we got prior to starting! (if I knew then, what I know now, etc.)

The only kingspan costs I have that may be of use to you is for their K17 board (37.5mm) at 10.50 odd + VAT, but that's an initial price before any argument. I'd suggest that you price around on insulation, ring the companies directly and ask for their rep where you're building and get a price off them directly as well as going through builders merchants.

On the mortgage front, it may be worth getting a QS to cost it for you, or else get some quotes from builders (who will generally use a QS). Beware of hidden costs in your budget! Once you have your figure, add on a margin (generous if the bank will approve it) and get your certifying engineer to knock out a spreadsheet for you with costs adding to your figure plus margin. You don't have to draw down your full amount - have approval for as much more than you think you'll need as you can get away with.

Best of luck,

Fergus.

Build Rite

dont dry line the inside.

and never mind an engineer for a 150mm cavity. if you want me to source an insulation quote you can PM me.

srdb20

Build Rite wrote: »

dont dry line the inside.

and never mind an engineer for a 150mm cavity. if you want me to source an insulation quote you can PM me.

may I ask why you have said this without giving any valid reason, please expand, elaborate or backup that post, more so that I can actually understand it please.

voodoo

Hi there,

We were looking at this also... worth speaking with your BER assessor... we had thought having a 120mm bumped cavity and a 52mm board (40mm insulation) would give a better U value but when we compared this to an 80mm board in the cavity and the 52mm dry line, the U value was way better... Also, XtraTherm gave a better U value than the Kingspan board...

we are looking at about €2000 for the insulation in the walls. Havent worked out the roof insulation costs yet (we will probably insulate the attic floor and the rafters too)

Build Rite

voodoo wrote: »

Hi there,

We were looking at this also... worth speaking with your BER assessor... we had thought having a 120mm bumped cavity and a 52mm board (40mm insulation) would give a better U value but when we compared this to an 80mm board in the cavity and the 52mm dry line, the U value was way better... Also, XtraTherm gave a better U value than the Kingspan board...

we are looking at about €2000 for the insulation in the walls. Havent worked out the roof insulation costs yet (we will probably insulate the attic floor and the rafters too)

Yes the board will give a better u value. But bead is a much better job as it fills the entire cavity. Corners can break off boards and if it is not completely tight to the inside leaf it doesn't work. A block layer doesn't care how the insulation goes in, and in most cases he won't fit it right, tape the joints etc.

Build Rite

srdb20 wrote: »

may I ask why you have said this without giving any valid reason, please expand, elaborate or backup that post, more so that I can actually understand it please.

Be cause there are several problems with drylining some being - air tightness. - it can cause concrete cancer, - and it moves the
dew point to the inside of the wall.
Not to mention the obvious problems like the difficulty of hanging kitchen units etc,

drylining shud only be done where completly neccessary. E.g. an Existing house situation with no other option

Regarding an engineer. Why would you?

sinnerboy

Build Rite wrote: »

Regarding an engineer. Why would you?

1. TGD Part A ( structure ) gives guidance on cavity ties up to 110mm
2. Homebond require cavities over this dimension to be designed by a Structural Engineer .

If you build a wider cavity without a structural engineer and it never fails well and good . If it fails .... your on your own in terms of rectification .

HereIGo

Build Rite wrote: »

Be cause there are several problems with drylining some being - air tightness. - it can cause concrete cancer, - and it moves the
dew point to the inside of the wall.
Not to mention the obvious problems like the difficulty of hanging kitchen units etc,

drylining shud only be done where completly neccessary. E.g. an Existing house situation with no other option

Regarding an engineer. Why would you?

Can you explain a bit more about air tightness, concrete cancer and the dew point?

sinnerboy

That poster has been given a week off for spamming at post 4 above .

He may choose to respond to you afterwards .

Kristopherus

There goes good advice until next week.

srdb20

Build Rite wrote: »

Be cause there are several problems with drylining some being - air tightness. - it can cause concrete cancer, - and it moves the
dew point to the inside of the wall.
Not to mention the obvious problems like the difficulty of hanging kitchen units etc,

drylining shud only be done where completly neccessary. E.g. an Existing house situation with no other option

Regarding an engineer. Why would you?

I wouldn't be a hundread percent on the insulation, that's why I asked for the reasoning. Still confused on the best option to go for

Poor Uncle Tom

Build Rite wrote: »

Yes the board will give a better u value. But bead is a much better job as it fills the entire cavity. Corners can break off boards and if it is not completely tight to the inside leaf it doesn't work. A block layer doesn't care how the insulation goes in, and in most cases he won't fit it right, tape the joints etc.

It is my opinion that bead will never completely fill a cavity, eg, behind cavity trays over angled curved or plain window or door heads.

You assume the people pumping the bead will do a 100% job, yet you also assume the person fitting the insulated board and the blocklayer fitting the cavity insulation will be carrying out shoddy work. Hardly a balanced viewpoint.

From that I can assume you are in some way related to the pumped insulation trade.

Build Rite wrote: »

Be cause there are several problems with drylining some being - air tightness.

If drylining is carried out properly there need be no problems with airtightness.

Build Rite wrote: »

...it can cause concrete cancer,

Total scaremongering, there is no such thing.

Build Rite wrote: »

- and it moves the
dew point to the inside of the wall.

The point at which interstitial condensation occurs will need to be considered and dealt with at the design stage of the build. This can be dealt with by good design of heating and ventilation systems for any build.

Build Rite wrote: »

Not to mention the obvious problems like the difficulty of hanging kitchen units etc,

Minor inconvenience which is easily overcome, ask any carpenter.

Build Rite wrote: »

drylining shud only be done where completly neccessary. E.g. an Existing house situation with no other option

This is your opinion only, and a very biased opinion, imo.

Build Rite wrote: »

Regarding an engineer. Why would you?

This comment speaks volumes on its own, and quite reckless.

Kristopherus wrote: »

There goes good advice until next week.

From a balanced viewpoint, that wasn't good advice being given. It was directed to steer readers to one particular construction method and material, pumped insulation. Build Rite can be thankfull I did not get to him first, it would have been a permanent ban.

muffler

Kristopherus wrote: »

There goes good advice until next week.

No, you were given very poor advice by that particular poster.

joanene

Thanks for all replies.
We have since done some more research and rang different insulation companies for quotes.
The engineer has approved the 150mm cavity so we are going with that.
We are still at early stages so have some time to fully decide on our insultaion products

HereIGo

PoorUncleTom, thanks for that post. We just built a new house with 150ml cavity and drylined the walls. I was awake half the night with worry. I can rest easy again.

hcvti

Currently Building a story and a half in cork that has 150mm cavity and 2500ft also.
Been getting prices of 2500-4500 for pumped bonded bead insulation for walls.
PM me if you want the name of the suppliers.
Currently a company in galway are the cheapest. But a friend of mine who is an engineer also has given me a name of an other company that he claims will do it cheaper.

soldsold

Hi Hcvti:

Would you PM the name of those two pumped insulation suppliers plz?

Thanks!

S