Insulation - am I going over the top

Eamon0224

Hi Guys,

I have a red brick 2 story hse from late 60's, with 100 cavity walls. there is no insulation in the walls and no insulation in the floor boards - just an 800mm void between the floor boards and the concrete slab.

I am considering getting
1. 10mm polymer render on Kingspsan Kooltherm K5 EWB external insulation fixed to existing brick facade

2. Filling existing cavity walls with Kingspan Ecobead Platinum blown insulation

3. Drylining; 37.5mm Kingspan Kooltherm K17 insulated plasterboard

4. install 60mm "Kingspan Kooltherm K3" or equivalent insulation between existing floor joists.

Does this seem over kill? or would you advise something different?

Gumbo

I would of thought the external insulation would not be needed with the full fill bead and internal dry lining? Have you done a calc on the U-Values to see if there's a benefit? Also the external stuff may need planning so it could be avoided too.

BryanF

Personally I'd be looking at the condition of the brick, and only if suitable pumping.
how many m2 of external walls are we talking? Have you considered doing the windows at the same time so you can get an insulation overlap and firring out the eaves it get the attic overlap and taking the insulation to ground or below to get flooring insulation overlap. Have you considered air-tight / vapour in floor.

4Sticks

Hire a BER assessor now to take all measurements and input a proposed series of improvements into the DEAP software ( which you can download for free from the SEAI website) .
Ask him / her to show you how to change the values for differing improvement measures.

Spread your efforts over 3 main aspects equally - insulation ( including windows ) - air tightness and ventilation - heating system efficiency design and controls.

I believe a studied analysis will reveal in a wider context that you would be overdoing the external wall at the expense of another vital element. It is not easy to go this alone.

Eamon0224

I want to change the look of the building, to do away with the red brick look and have a white plaster look instead. The architect advised getting external insulation instead of just skimming over the brick, he said the cost would be ablout the same but now as part of the external insulation we're looking at removing all the existing windows and adding new cills so the job is growing legs....

So I was thinking, is it sufficient to get the cavity pumped and do the internal insulation and just skin the outside and leave the windows as they are? cost is obviously a factor.

I guess I should get the u value calculation.

The size is 173 m sq. Anybody know what's a typical rate per m sq for external insulation?

BryanF

Plastering is cheaper that an Ewi system. Ewi - a very approx rule if thumb is 100€ pm2

Id recommend a phpp assessment given the size of what you will be heating

hexosan

Eamon0224 wrote: »

Anybody know what's a typical rate per m sq for external insulation?

Approx €100/m2

Gumbo

Eamon0224 wrote: »

So I was thinking, is it sufficient to get the cavity pumped and do the internal insulation and just skin the outside and leave the windows as they are? cost is obviously a factor.

Think of it this way, its like skimming a shoe box and then removing the lid. It doesnt matter how good the walls are if everything will just flow out the windows.

But saying that if this is a long term goal, ie get the walls done now and upgrade the windows in a year or tow or when funds allow then it would make senseto do the walls as good as possible now i suppose.

A full BER would show exactly where you should upgrade etc and will cost next to nothing compared to other costs in your renovations and it will save you the fee over the first year or less imho.

MicktheMan

4Sticks wrote: »

Spread your efforts over 3 main aspects equally - insulation ( including windows ) - air tightness and ventilation - heating system efficiency design and controls.

I believe a studied analysis will reveal in a wider context that you would be overdoing the external wall at the expense of another vital element. It is not easy to go this alone.

^^^^This.

Insulation addresses only one of the typical heat loss mechanisms of a house (and in the Irish context, the lesser one).
Don't neglect air tightness and ventilation.
Then heating system efficiency and controls get a lot easier

Eamon0224

MicktheMan wrote: »

^^^^This.

Insulation addresses only one of the typical heat loss mechanisms of a house (and in the Irish context, the lesser one).
Don't neglect air tightness and ventilation.
Then heating system efficiency and controls get a lot easier

Thanks for the good advice, what should I be doing for air tightness and ventilation? I did look at a heat recovery system but it was 20k so I took it out of the budget.

JD6910

you need to weight up the cost of doing a measure and what it does for the u-value etc....cost benefit analysis...

glashanator

Eamon, no one person could get everything you need to know into one post about airtightness and heat recovery.

scroll through the many threads that have been on both topics. There are anything up to 5 years worth here on boards.

20 k sounds excessive for mhrv. You should only be looking at between 4-7k. I'd revisit that and get an initial quote from a company. Get a ball park,then you know is it in ur budget.

one thing most will tell you here is if you are considering airtightness, you will need ventilation, they go together and are pretty much needed together. In other words, you need good level of airtightness for ur HR to work, and if your AT is good you need ventilation to protect from mould and condensation.

lastly, if you are a total noob to these, you can do AT AND insulation courses in athboy for 95 quid. Money well spent and only lasts a day, everything is well explained.certainly helped me last year.

MicktheMan

Eamon0224 wrote: »

Thanks for the good advice, what should I be doing for air tightness and ventilation?

First step is to have the house tested for air leakage and appropriate solutions listed taking into account your plans for the house.

MicktheMan

Eamon0224 wrote: »

I did look at a heat recovery system but it was 20k so I took it out of the budget.

:eek:
Something wrong here.

galwaytt

Eamon0224 wrote: »

Thanks for the good advice, what should I be doing for air tightness and ventilation? I did look at a heat recovery system but it was 20k so I took it out of the budget.

something very seriously wrong with that 20k figure. I paid (admittedly 2007), €4500 .....how on earth you could be asked for 20k escapes me.......

sydthebeat

I think they may be confusing it with a heat pump system?