Floor insulation query without UFH

Lynch32

sorry to be starting another insulation thread.

I've asked the builder to allow for 100 mm floor insulation which he has. However from speaking with my engineer at the weekend he told me this was overkill as we weren't going with UFH and that we were adding unnecessary cost.
The way I see it I've not choice now, as if we go with 50 mm now, the remainding height will have to be made up with addition screed and this will almost cost the same. So the way I see it I might as well go with the 100 insulation now (instead of additional screed)
Just wondering is 100 mm too much if you don't have ufh. I am a little annoyed with myself for not researching this better to start of with:(
It would be great if you could advise if I went overboard here, for little gain.

Also I told the engineer I was planning to dryline using 50 mm. We already have 80 mm kingspan in the cavity. He said this was over the top again and 25mm would be more than sufficient. I thought the thicker the better. Do you think 80 cavity + 25 mm dryline (both kingspan) is more than sufficient. Or should I go the extra expense and upgrade to 50.

I want to upgrade my insulation but only to the point where it makes sense.

Thanks in advance for comments:)
Thanks
Sharon

sinnerboy

Within reason , you can't over insulate .

Passive houses typically use around 300mm insulation in floors and walls - 500mm+ to roofs

Oil is at record high price - it has not stopped rising

what seems over the top today will not be considered so in future

Slates

Lynch32 wrote: »

sorry to be starting another insulation thread.

I've asked the builder to allow for 100 mm floor insulation which he has. However from speaking with my engineer at the weekend he told me this was overkill as we weren't going with UFH and that we were adding unnecessary cost.
The way I see it I've not choice now, as if we go with 50 mm now, the remainding height will have to be made up with addition screed and this will almost cost the same. So the way I see it I might as well go with the 100 insulation now (instead of additional screed)
Just wondering is 100 mm too much if you don't have ufh. I am a little annoyed with myself for not researching this better to start of with:(
It would be great if you could advise if I went overboard here, for little gain.

Also I told the engineer I was planning to dryline using 50 mm. We already have 80 mm kingspan in the cavity. He said this was over the top again and 25mm would be more than sufficient. I thought the thicker the better. Do you think 80 cavity + 25 mm dryline (both kingspan) is more than sufficient. Or should I go the extra expense and upgrade to 50.

I want to upgrade my insulation but only to the point where it makes sense.

Thanks in advance for comments:)
Thanks
Sharon

120m² of 100mm quinntherm put in my floor 2 weeks ago €1330+vat

Tell your engineer that there is no such thing as "overkill" when it comes to insulation

sydthebeat

Sharon.... get rid of that engineer, what a wally!!

"the first rule of insulation is that you cant have too much insulation"
*a la fightclub*

i cant believe a person who purports himself to be a professional is recommending you NOT to better the construction....

Keep your 100mm insulation in the floor, keep your 50mm insulated plasterboard..... The increased levels of insulation will restrict the diffusion of heat out of your dwelling to a higher degree, and thus will result in your conservation of fuel, thus lowering your running costs.

obviously everyone has a budget to work to, and if you can afford your specification, stick to it.....

Lynch32

This is what I thought!! thanks for putting my mind at ease. My engineer made me feel like i was being silly and as for my builder he just thinks I am obsessed with insulation:D. He just doesn't get the whole upgrading of insulation. He even suggested that 150 of the fiber glass stuff on the ceiling was sufficient, even though this doesn't even meet builders regulations. I am thinking more in the line of 400 mm of the stuff.


When your engineer and builder tell you its not necessary - u begin to doubt yourself.

thanks for your comments
S

Lynch32

sydthebeat wrote: »

Sharon.... get rid of that engineer, what a wally!!

"the first rule of insulation is that you cant have too much insulation"
*a la fightclub*

i cant believe a person who purports himself to be a professional is recommending you NOT to better the construction....


Strangely enough the enginner is very well respected in the area - over 30 years experience. This is why I was a little surprised and disappointed. He is very old school though, but known to be a stickler when it comes to detail. This is why we hired him. Hope he knows more about the structural side of things (for my sake) as he clearly isn't uptodate with insulation !!

Thanks again

Gumbo

nothing at all wrong with 100mm insulation, we are supervising a build at the moment and they are using 140mm kingspan kooltherm in the floor!

Mellor

Lynch32 wrote: »

Strangely enough the enginner is very well respected in the area - over 30 years experience. This is why I was a little surprised and disappointed. He is very old school though, but known to be a stickler when it comes to detail.

This is common enough, older guys who remember the days before insulation. Are a little behind the times and think that insulation is insulation, and 50mm is the magic number.
Food for thought, I can't remember the days when any less than 70-80mm was enough

bertie1

I put in 4" insulation ( high density) in my floors ( I have under floor heating ) 2 " high density kingspan in the cavity & 50 mm insulated slab on all the external walls afterwards. Having spent the first winter in the house I must say I am very happy with the comfort levels.

In the ceilings I got the slabbers to screw 50 mm insulated slabs to the joists & insulated above them again with 4" fiberglass.

Your engineer is giving you the minimum requirements

whitestew

we're going for 150 cavity pumped with glued beads, 120 mm k3 in floor and 300mm pumped cellulose in roof. and still don't think that's enough!

ardara1

whitestew wrote: »

we're going for 150 cavity pumped with glued beads, 120 mm k3 in floor and 300mm pumped cellulose in roof. and still don't think that's enough!

Whats the reasoning for the K3 in the floor - I thought it was a fire boards?
Ordinary Kingspan Polyiso would be a hell of a bit cheaper with little or no difference in performance.?

muffler

sydthebeat wrote: »

Sharon.... get rid of that engineer, what a wally!!

"the first rule of insulation is that you cant have too much insulation"
*a la fightclub*

i cant believe a person who purports himself to be a professional is recommending you NOT to better the construction.

No. no. no. Dont get rid of im (not just yet anyhow).

Get him to sign up here and explain his thinking - and the get rid of him.,

Lynch32

thanks for your comments/advice. I was originally worried that was putting in too much insulation in, now I am worried I am not putting enough insulation in:D.
I guess i will put in as much as I possibly can afford.I just won't worry about my engineer and the builder on that aspect of the build.
I won't sack the engineer just yet as I "think" he is much better and has more interest in the structural side of things (although I understand why it was suggested:))

Also did someone mention that insulation prices where going to rise on the 1st June? Is that really on the cards?


Cheers

Bobby04

Lynch32 wrote: »

Strangely enough the enginner is very well respected in the area - over 30 years experience. This is why I was a little surprised and disappointed. He is very old school though, but known to be a stickler when it comes to detail. This is why we hired him.

Very well respected by who? I suspect by "old school" builders, and uninformed customers! I had some extremely well respected tradesmen work on my house who were constantly harping on about me "having more money than sense" etc. because I wanted to install insulation above the bare minimum to meet regulations. And I can empathise with feeling rather stupid when supposed experts are critising your choice of insulation. My "sanity test" now is to compare everything to the levels used in a passive house!

whitestew

ardara1 wrote: »

Whats the reasoning for the K3 in the floor - I thought it was a fire boards?
Ordinary Kingspan Polyiso would be a hell of a bit cheaper with little or no difference in performance.?

we hired an energy and renewables consultant who told us what we should be doing regarding insulation and how to heat the house. came and looked at house, site and asked us all about how we would be living. this was his solution.

sydthebeat

the K stands for Kooltherm and the 3 represents its purpose ie under floor....

K3 is the standard underfloor insulation from kingspan, its not specifically a fire proofing board.... for some reason they seem to be moving away from specifying thermafloor TF70 under floors....

K3 is a pheonlic material, and yes, has slightly better fire proofing properties than polyiso (ie the thermafloor TF70)....

sandt

Lynch32 wrote: »

Also did someone mention that insulation prices where going to rise on the 1st June? Is that really on the cards?


Cheers

any truth in this???

i gotta get buying if thats the case!!

sydthebeat

I think people may be getting confused....

The conservation (insulation) regulations are changing for any house applied for permission after 1st july... not prices AFAIK....

NB.
The new regs look at a whole house situation, in which insulation is just one factor...



http://www.neta.ie/pdf/2008_building_regulation_changes_part_L.pdf

Conservation of Fuel and Energy

L1 A dwelling shall be designed and constructed so as to ensure that the energy performance of the
building is such as to limit the amount of energy required for the operation of the dwelling and the
amount of CO2 emissions associated with this energy use insofar as is reasonably practicable.

L2 For new dwellings, the requirement of L1 shall be met by
a. providing that the energy performance of the dwelling is such as to limit the calculated primary
energy consumption and related CO2 emissions insofar as is reasonably practicable, when both
energy consumption and CO2 emissions are calculated using the Dwelling Energy Assessment
Procedure (DEAP) published by Sustainable Energy Ireland;
b. providing that, for new dwellings, a reasonable proportion of the energy consumption to meet the
energy performance of a dwelling is provided by renewable energy sources;
c. limiting heat loss and,where appropriate, availing of heat gain through the fabric of the building;
d. providing and commissioning energy efficient space and water heating systems with efficient heat
sources and effective controls;
e. providing that all oil and gas fired boilers shall meet a minimum seasonal net efficiency of 86%;
f. providing to the dwelling owner sufficient information about the building, the fixed building services
and their maintenance requirements so that the building can be operated in such a manner as to
use no more fuel and energy than is reasonable

L3 All oil and gas fired boilers installed as replacements in existing dwellings shall meet a minimum seasonal

net efficiency of 86% where practicable.

donothoponpop

I've been shopping for Kingspan and Xtratherm in the past week, and have been told directly by reps that prices are going up 8% from June 2nd.

-donothoponpop

whitestew

was at the Galway self build and a kingspan sales rep told me that the prices were indeed changing. isn't insulation made from petrochemicals so i'm sure it rises in price with oil??

Slig

thats for all the dinosaurs still insistant on using the traditional cavity wall system, smart move by kingspan IMO. pity we are still gonna get screwed by all the new technologies aswell:D

Go Greens, way to mess up the building trade even more!!! and screw the consumer in the process!
dont get me wrong I agree with highly efficent houses but I think it should be a choice like buying a big car. the stick is already there with the BER system and the carrot is lower running costs. I'd like to see the reaction if they tried banning cars with high emission rates from entering the country.

RKQ

sydthebeat wrote: »

Sharon.... get rid of that engineer, what a wally!!

"the first rule of insulation is that you cant have too much insulation"
I cant believe a person who purports himself to be a professional is recommending you NOT to better the construction....

I agree fully with sydthebeat......
100mm aeroboard or 55mm High Density foil back insulation is now the minimum requirement of the current Building Regulations. Has your "Engineer" read the Regulations. Aeroboard is only €15 for a 8'x 4' sheet, foil backed is three times that! The payback on insulation is very fast. Always try to exceed the minimum requirements of the Building Regulations.

ardara1

sydthebeat wrote: »

the K stands for Kooltherm and the 3 represents its purpose ie under floor....

K3 is the standard underfloor insulation from kingspan, its not specifically a fire proofing board.... for some reason they seem to be moving away from specifying thermafloor TF70 under floors....

K3 is a pheonlic material, and yes, has slightly better fire proofing properties than polyiso (ie the thermafloor TF70)....

Why would you need a fire board when it's under 4" of concrete - whats the advantage over TF70?

sydthebeat

ardara1 wrote: »

Why would you need a fire board when it's under 4" of concrete - whats the advantage over TF70?

I think thermafloor only goes up to 70mm thick, so it you want better floor u values you need to use a kooltherm product...
this may or may not be the case, i suppose you could ask kingspan why the recommend kooltherm over thermafloor for anything over the minimum regulation......
the thermal conductivity of polyiso seems to reduce the thicker it gets, whereas the thermal conductivity of phenolic seems to get better the thicker it gets *

* points of reference
Kingspan Insulation quick guide
Future proof solutions :- Kingspan

Slates

sydthebeat wrote: »

I think thermafloor only goes up to 70mm thick, so it you want better floor u values you need to use a kooltherm product...
this may or may not be the case, i suppose you could ask kingspan why the recommend kooltherm over thermafloor for anything over the minimum regulation......
the thermal conductivity of polyiso seems to reduce the thicker it gets, whereas the thermal conductivity of phenolic seems to get better the thicker it gets *

* points of reference
Kingspan Insulation quick guide
Future proof solutions :- Kingspan

Thermafloor comes up to 100mm thick and more...........

Maby they are pushing Kooltherm because of the profit margin, its way more expensive than the Therma product range even though there is minimal difference in the thermal conductivity ??

sydthebeat

Slates wrote: »

Thermafloor comes up to 100mm thick and more...........

Maby they are pushing Kooltherm because of the profit margin, its way more expensive than the Therma product range even though there is minimal difference in the thermal conductivity ??

could very well be the reason.....

sinnerboy

very thick boards under relatively thin screed can cause curling

better to use 2 x 60 boards , staggered than 1 x 120

and dont forget 500 gauge ploythene to protect foil face from wet screed over

( wow has this thread got legs )

Mellor

Phenolic proforms slightly better, in terms of equal prices, however, in therms of equal cost per square metre, polyiso does better.
The phenolic had got the additional advantage of being of a similar fire resistance to mineral wool


I seen aeroboard was mentioned, aeroboard has a pretty poor proformance, and to get the same value as polyiso you need to increase thickness by c.40%,

Slates

sydthebeat wrote: »

could very well be the reason.....

60mm Thermafloor €7.70 per m²
60mm Kooltherm K3 €14.00 per m²

100mm Thermapitch TP10 €14.00 per m²
100mm Kooltherm K7 €23.00 per m²

as the yanks say "you do the math !" .............

sydthebeat

thanks slates...

as a matter of interest, whats the price difference between thermawall TW50 and Kooltherm K8?

Lynch32

sandt wrote: »

any truth in this???

i gotta get buying if thats the case!!

I just rang kingspan and YES insulation is going up 8% from Monday onwards:eek:
Anything delivered by this Friday evening will be at the current price.