Insulation /question

[Taydo]

Forgive me if this has been asked already. What insulation is included in a standard builders finish. What extra insulation would you reccomend as a worthwhile addition. Answers on a Postcard please to PO.Box I Know Sweet FA about Building. St Moritz Halting Site. Dublin 44.

 

[davidoco]

You don't want to be agreeing a house build with a builder with just the phrase "standard builders finish".

That phrase used to mean insulation to standards prevailing at the time "Building Regulations - Part L" available on sei.ie and each builder would vary on what insulation they would put in to scrape within those regulations. Follow the attached link and see what they could put in to meet the minimum spec

You need to look at the U Value required see [broken link removed]

Note my understand is that the regulations have changed and that the following should appear in bold on those pages

roofs (insulated on flat) 0.16 W/mK
roofs (insulated on pitch) 0.2 W/mK
walls 0.27 W/mK
ground floors 0.25 W/mK

(post edited to show correct values required)

What extra insulation ????? That's the million dollar question - you will find people putting in 200mm polyurethane in floor, full fill cavity insulation with insulation backed plasterboard on the inside, 300mm to 500 mm fibreglass in attic.

Remember double the insulation does not halve the heat loss figures.

 

[Taydo]

Thanks for that. Won't be able to do floor or External walls as they are already done but would be anxious to know wht you would recommend for underneath wood flooring, internal walls and attic??? Again thanks very much for the info it does help a lot.

 

[sydthebeat]

sorry david, those figures are incorrect.

min u values:

roofs (insulated on flat) 0.16 W/mK
roofs (insulated on pitch) 0.2 W/mK
walls 0.27 W/mK
ground floors 0.25 W/mK


to the OP, dont let the builder specify your insulation, its the job of your certifier to certify compliance with building reg... so ask him / her.

You are legally required to get a Building Energy Rating (BER) done... so my best advice would be to hire a BER assessor to do a prelimanary assessment on the plans and develop an insulation specification from this.

 

[Taydo]

Thanks Syd, didn't know you were legally obliged to get a BER done, Building Virgin me. Will do that, how much do they cost and would they still be able to do an assesment eventhough the Floor has been poured and Walls are up????

 

[davidoco]

sorry david, those figures are incorrect.

Thanks - original post amended for clarity, they keep changing the goal posts on values needed. My own particular house got permission in or around 2002, built in 2005 and occupied in 2007 and I understand the levels have changed twice in that time.

..... floor and External walls already done but would be anxious to know wht you would recommend for underneath wood flooring, internal walls and attic??? Again thanks very much for the info it does help a lot.

Out of interest do you know what went into the floor and walls. Half the battle may have been lost already! For the sake of your sanity get a BER assessment done (you'll require it in any event), consider your rating, then you'll have loads of questions about insulation.

 

[sydthebeat]

Thanks Syd, didn't know you were legally obliged to get a BER done, Building Virgin me. Will do that, how much do they cost and would they still be able to do an assesment eventhough the Floor has been poured and Walls are up????

yes, the legal requirement is to get the assessment done prior to you occupying the dwelling, but many clients choose to get a preliminary assessment done off the plans so they can make selections during teh build, ie insulation, heating system and controls etc.

it would be an idea to get an assessor on board now as theres a certain amount of information you need to retain in order to get the best possible rating on assessment, mainly product names and serials etc.

 

[sfag]

techniical info all very well but can someone translate those regulation figures into actual insulation dimensions

eg what thickness of kinhspan high density does one use for walls. it used to be 60 mil. Is it more?

 

[sydthebeat]

techniical info all very well but can someone translate those regulation figures into actual insulation dimensions

eg what thickness of kinhspan high density does one use for walls. it used to be 60 mil. Is it more?

sfag, say you have two dwellings

one is a detached 1350 sq ft bungalow
the other is a 1350 sq ft 2 storey semi-d

under the new regs (2007 part L) the two dwellings could require different insulation thicknesses in the walls (of the same material) to comply with regulations... why??

because the bungalow has a lot more exposed wall surface area for heat to escape from than the semi-d..... if you picture the actual shapes it becomes obvious.

then say you consider the air tightness of each.. .say the bungalow is 25% less air tight than the semi d.. it may require 25% more insulation to meet the same energy efficiency criteria.

The days of simply specifying a thickness for floor / wall / roof are over. the whole house has to be looked at as one entity, with all factors such as orientation, solar gains, air tighntess, heating system and controls etc

 

[davidoco]

techniical info all very well but can someone translate those regulation figures into actual insulation dimensions

eg what thickness of kinhspan high density does one use for walls. it used to be 60 mil. Is it more?

from [broken link removed]
Only the last last three items in this list can meet the 0.27 W/mK requirement, athough 60mm of TW50 from Kingspan in a cavity will give 0.27 - see note below

Cabity Wall Insulation

100mm blown polystyrene, mineral wool, cellulose fibre
0.30
60mm extruded polystyrene insulation
0.40
35mm polyurethane foam board
0.39
35mm phenolic foam board
0.37
Timber frame 150 mm, mineral quilt
0.25
Timber frame 140mm, cellulose fibre
0.19
Safewarm home construction
0.31​

Note the above take no account of building volume, area of heat loss elements or air tightness as described by sydthebeat.

Excellent guide here [broken link removed]

 

[Taydo]

Lads and Lassies, I'm confused had a chat with my engineer at lunchtime and He said that you anly need a BER legally when selling a house not when you are using it as your home like me. All thoughts greatly appreciated.

 

[sydthebeat]

Lads and Lassies, I'm confused had a chat with my engineer at lunchtime and He said that you anly need a BER legally when selling a house not when you are using it as your home like me. All thoughts greatly appreciated.

This post will be deleted if not edited immediately, even the professionals dont know the bloody law...

taydo....
show him this:
[broken link removed]

point him towards paragraph 7 (1)..... which states

7. (1) A person who commissions the construction of a building of a class referred to in subparagraph (a) or (b) of paragraph (4) construction of which commences on or after such date specified for that class in the said subparagraphs shall, before such building is occupied for the first time, secure a BER certificate (in the form prescribed by the First Schedule or Second Schedule to these Regulations, as appropriate) and advisory report in relation to the building and shall produce a printed copy of such BER certificate and advisory report to the building control authority in whose functional area the building is situated, on demand being made by that authority for its production.

(5) The provisions of subparagraphs (a) and (b) of paragraph (4) shall not apply to the following buildings – ​

(a) a new dwelling for which planning permission was applied for or a planning notice was published on or before 31 December 2006 , and where substantial work is completed by 30 June 2008;




[FONT=Arial,Arial][FONT=Arial,Arial]I have bolded up the relevant wording.[/FONT][/FONT]

[FONT=Arial,Arial][FONT=Arial,Arial]To be honest, it doesnt fill me with much confidence that your 'engineer' isnt up to speed with a law thats in place now nearly 2 years!![/FONT][/FONT]
[FONT=Arial,Arial][FONT=Arial,Arial][/FONT][/FONT]
[FONT=Arial,Arial][FONT=Arial,Arial][/FONT][/FONT]
[FONT=Arial,Arial][FONT=Arial,Arial]Edit: corrected operative dates[/FONT][/FONT][FONT=Arial,Arial][FONT=Arial,Arial]
[/FONT][/FONT]

 

[davidoco]

....... I'm confused .......

Whatever about the legal requirement, a few hundred euro spent now on an assessment may save you thousands in the years ahead. Even the fact that you have a BER Assessment means that the wool (no pun intended if you go down that route) cannot be pulled over your eyes by a builder throwing in 150mm fibreglass in the attic because that's the way he's used to doing it.

 

[Taydo]

Thanks Syd but in fairness too him the building did commence before 01 July 2008 so maybe I'll give him the benefit of the doubt that said and done if there was an exam in Common Sense they wouldn,t let him even sit it.

 

[Taydo]

I'll probably get it done anyway as David says iy will benefit us in the long run.

 

[sydthebeat]

Thanks Syd but in fairness too him the building did commence before 01 July 2008 so maybe I'll give him the benefit of the doubt that said and done if there was an exam in Common Sense they wouldn,t let him even sit it.

i actually have wrong dates bolded above taydo....

the regs state the the dwelling would need to be 'substantially complete' before 30 june 2008..

ill find it and edit the above post.

 

[glic83]

we move into our house a few months back,is there a minium standard of insulation that has to be put into an attic my house is a new build but when i was up in the attic the other day there was a few gaps either side of the insulation and the joists?im going to have to put more insulation in but i just wanted to know if there is a certain standard that the insulation in the house sould be up to

 

[sydthebeat]

we move into our house a few months back,is there a minium standard of insulation that has to be put into an attic my house is a new build but when i was up in the attic the other day there was a few gaps either side of the insulation and the joists?im going to have to put more insulation in but i just wanted to know if there is a certain standard that the insulation in the house sould be up to

did someone certify the build??

can you tell us what product is in your attic.... wool fibre or rigid board?
and approx what thickness?

 

[glic83]

certify as in an enery rating for the house?no, just moved into the house there when i came home from oversea's in september,its wool fibre and i havent got the thickness will check it out in a bit

 

[sfag]

sfag, say you have two dwellings

one is a detached 1350 sq ft bungalow
the other is a 1350 sq ft 2 storey semi-d

under the new regs (2007 part L) the two dwellings could require different insulation thicknesses in the walls (of the same material) to comply with regulations... why??

because the bungalow has a lot more exposed wall surface area for heat to escape from than the semi-d..... if you picture the actual shapes it becomes obvious.

then say you consider the air tightness of each.. .say the bungalow is 25% less air tight than the semi d.. it may require 25% more insulation to meet the same energy efficiency criteria.

The days of simply specifying a thickness for floor / wall / roof are over. the whole house has to be looked at as one entity, with all factors such as orientation, solar gains, air tighntess, heating system and controls etc

Didn't appreciate that fact. Gawd is sounds complicated. Y'know there is no such thing as building control in this country (they have it in the North) so who is going to police these things?.