External Wall Insulation

kennyb3

Considering having this done to house - back & gable wall and cavity pump for brick finished front.

Have got a range of rough quotes from €7k post grant to about €11k.

Have a few of the company's at various price ranges coming to do a site survey for more accurate quote and to chat about what's involved etc.

What questions should I be specifically be asking? An obvious one seems to be about how they will over come pebble dash.

Most of these companies are high up on google searches - how do I know which one to go for?

If anybody could PM me recommendations I'd appreciate it - particularly if you are an Archtech or similar.

This has me quiet worried about not getting the right contractor - and there are 55 names you could go with on google.

Also as per pg 11 & 13 the airtightness decreased - is this due to additional ventilation required? A lot of EWI installers claim increased airtightness so I was confused by this.

MicktheMan

kennyb3 wrote: »

1. What questions should I be specifically be asking? An obvious one seems to be about how they will over come pebble dash.

2. Most of these companies are high up on google searches - how do I know which one to go for?

3. If anybody could PM me recommendations I'd appreciate it - particularly if you are an Archtech or similar.

4. This has me quiet worried about not getting the right contractor - and there are 55 names you could go with on google.

5. Also as per pg 11 & 13 the airtightness decreased - is this due to additional ventilation required? A lot of EWI installers claim increased airtightness so I was confused by this.

1. Ask how they propose eliminating thermal looping between the wall and the insulation. If they don't understand the question, move on. If they tell you not to worry about it, move on.

2. Research, research, research. Ask for previous references and go visit the house, householders from jobs completed recently and not so recently. Remember that being registered on the SEAI register means little from a quality point of view.

3. Where is the house?

4. Caveat Emptor big time

5. EWI has NOTHING to do with airtightness, don't let anybody tell you otherwise.

Other questions / comments:
Will they insulate past the soffit and down to the footings?
What type of walls do you gave?
Why are you considering EWI? What is your current air tightness?
If EWI is being seriously considered, have you thought about replacing your windows and moving them out flush with the outer wall surface (if not replacing your windows, the current windows might be able to be moved). This will allow a thicker insulation and much much better thermal bridging detail.

BryanF

kennyb3 wrote: »

Considering having this done to house - back & gable wall and cavity pump for brick finished front.

Have got a range of rough quotes from €7k post grant to about €11k.

Have a few of the company's at various price ranges coming to do a site survey for more accurate quote and to chat about what's involved etc.

What questions should I be specifically be asking? An obvious one seems to be about how they will over come pebble dash.

Most of these companies are high up on google searches - how do I know which one to go for?

If anybody could PM me recommendations I'd appreciate it - particularly if you are an Archtech or similar.

This has me quiet worried about not getting the right contractor - and there are 55 names you could go with on google.

Also as per pg 11 & 13 the airtightness decreased - is this due to additional ventilation required? A lot of EWI installers claim increased airtightness so I was confused by this.

how not to detail ewi www.daft.ie/1994618
Consider the eaves details, ground, windows, any protrusions etc

Bullocks

BryanF wrote: »

how not to detail ewi www.daft.ie/1994618
Consider the eaves details, ground, windows, any protrusions etc

We do a bit of EWI and its lads like that coming in with €200 worth of flashing jammed under barges and under eaves that will get alot of the jobs because there is no comparison in price if you want to go extending the roof or getting proper barge cappings folded and fitted .
In a few years time when the gutter gets blocked and starts leaking down behind the finish that the fun will start with alot of these jobs

BryanF

Bullocks wrote: »

We do a bit of EWI and its lads like that coming in with €200 worth of flashing jammed under barges and under eaves that will get alot of the jobs because there is no comparison in price if you want to go extending the roof or getting proper barge cappings folded and fitted .
In a few years time when the gutter gets blocked and starts leaking down behind the finish that the fun will start with alot of these jobs

What 'constructive' solution would you put forth for your industry?
More regulations?
An Ewi governing body who pays out if repairs are required?
Installer insurance paid up front for the duration of any guarantee?
Name and shame website for crap Workmanship etc

Bullocks

BryanF wrote: »

What 'constructive' solution would you put forth for your industry?
More regulations?
An Ewi governing body who pays out if repairs are required?
Installer insurance paid up front for the duration of any guarantee?
Name and shame website for crap Workmanship etc

I have no constructive solution , except not to bother pricing any EWI this year myself ,(I suppose thats not constructive to anyone except myself ! )
There are regulations and guidelines how it should be done , but I suppose they arent being enforced .
An installer insurance tied in with a EWI governing body would be worthwhile idea
Dont know about a name and shame website , lads will just change names and companies - I stripped and redid a house last year that had all the acrylic falling off and damp gone in behind the insulation , it was only 5 yrs done but a few silly bits of obvious waterproofing were left out which let the whole thing fail .
The original company were gone when the homeowner went to get them back .

ggt657

Folks,

Has anyone got any company recommendations for the EWI (please pm me if you don't want to name them)? I'm looking to get it done but I don't know many that have it done already, for any length of time.

Thanks,

Gav.

BryanF

ggt657 wrote: »

Folks,

Has anyone got any company recommendations for the EWI (please pm me if you don't want to name them)? I'm looking to get it done but I don't know many that have it done already, for any length of time.

Thanks,

Gav.

http://www.boards.ie/vbulletin/showthread.php?t=2056682402&page=25

Persius

kennyb3 wrote: »

Considering having this done to house - back & gable wall and cavity pump for brick finished front.

Have got a range of rough quotes from €7k post grant to about €11k.

...

I'm guessing that you're doing EWI for back and gable wall because they're "cavity block" (aka hollow block) walls with pebbledash finish.
Your front wall is presumably a "cavity wall" with red brick in the front and 4-inch concrete block behind with a cavity in-between (probably empty).

This sounds similar to my own house. I also looked into EWI. I was advised by two builders that it was a waste of time for cavity block walls as all the heat escapes out through the alligned cavities in the blocks. If there's no internal insulation, this seems logical to me. Heat goes out through the wall, enters the cavities and shoots up and out the attic.

A third builder said that EWI was OK as long as you used spray insulation to insulate the inside of the roof as well. I.e. heat escapes up to attic, but once attic reaches same temperature as rooms, then no more heat loss. I'm very skeptical of this explanation.

There's a frequently referenced series of articles by Joseph Little Architect, called "breaking the mould". He appears to recommend EWI for cavity block walls. However, in article 2, he does state "What is missing in the study above (see A3) is the additional impact of the vertical air flow within the linked hollows of uninsulated blocks".

In a more recent Passivhouseplus retrofit article, he recommends that if you use internal wall insulation, make sure the U value is not smaller than 0.5. He doesn't recommend going down to 0.27 (which is required by SEAI to get the grant) as you need some heat going into the blocks to dry them out and prevent external damp reaching the inside.

My current thinking is also to use thinner dry lining with a not-too-low U-value. It's much cheaper than EWI. Even though you don't get the SEAI grant, using thinner dry lining is much cheaper than using dry lining with a U value of 0.27. So it evens out. I will accept higher heating bills if I can avoid condensation, damp and mould. And I should still have lower heating bills and a warmer house than I currently have - at least I hope so ... (besides, all the windows surely have a U value higher than 0.5)

BryanF

So To sum up: your going with drylining because you won't overlap the wall insulation with the ceiling/roof insulation? You can see this is a Flawed argument, elsewhere Little explains how to deal with this issue -infact that's what we're taking about in this thread above when we talk about 'proper detailing'

I have specified Ewi and pumped the cavity first and I've specified Ewi on hollow block work where the top of wall/wall plate area needed sealing - in both cases Ewi was the best solution to avoid thermal bridges, and yes footings, eaves, windows etc were considered.

I respect the need to retain a brick facade in certain circumstances but otherwise external insulation is the way to go, assuming it's detailed & installed correctly.

I also agree with the .5wm2k drylining in solid construction - this is often overlooked as is the need for a vapour barrier on the warm side of the insulation, amongst other specification/detailing issues.

Bullocks

There is a brick facade finish to go over EWI if you want to keep the brick look .

slipstream

Bullocks wrote: »

There are regulations and guidelines how it should be done , but I suppose they arent being enforced .

Would you guys mind listing the best sources you know of on how to properly detail EWI?

Perhaps decent guidelines would enable end customers to challenge installers.

Slip

Bullocks

slipstream wrote: »

Would you guys mind listing the best sources you know of on how to properly detail EWI?

Perhaps decent guidelines would enable end customers to challenge installers.

Slip

I wouldn't be the best to put up links , or indeed be an expert but there might be details on the SEAI website or the Weber , Baumit or Greenspan sites.

Persius

BryanF wrote: »

So To sum up: your going with drylining because you won't overlap the wall insulation with the ceiling/roof insulation? You can see this is a Flawed argument, elsewhere Little explains how to deal with this issue -infact that's what we're taking about in this thread above when we talk about 'proper detailing'

I have specified Ewi and pumped the cavity first and I've specified Ewi on hollow block work where the top of wall/wall plate area needed sealing - in both cases Ewi was the best solution to avoid thermal bridges, and yes footings, eaves, windows etc were considered...

How do you seal the top of the wall/wall plate? Especially at the gable end?
I went up to the attic to have a look at the gable end currently. Wasn't sure how it could be sealed in to prevent air/heat loss.

BryanF

lift the last few rows of slates-tiles & felt. From there assess best course of action.

Persius

Thanks, appreciate the answer.

It seems to be quite expensive to do EWI properly.
As you say, may have to lift tiles and felt and replace.
I've seen it said elsewhere that EWI should extend down to the foundation. So need to dig out channel and potentially move drain pipes if downpipes go to ground too close to wall,
Also read that you may need to replace facia/soffit and possibly even extend out roof gutters.
All this adds to the cost.

Makes me wonder if it's economically worth it. I.e. how much will it reduce my heating bills by, and how many years of heating bills do I need to break even? Just not sure if it stacks up.

Added to that is the risk that the lay person (e.g. me) does not know enough about this to even be able to distinguish the true professional from the cowboy or even well-meaning amateur. It seems that the risk is too high that a installer is chosen who does a sub-optimal job, resulting in minimal heat bill savings, and potentially even causing damage due to damp/mould build up in thermal bridges that were not considered.

Don't get me wrong, I'm knocking EWI per se. In fact, I would really like to get it done to two of the four walls on my house. But I'm finding it hard to justify the cost and risk.

BryanF

Persius wrote: »

Thanks, appreciate the answer.

It seems to be quite expensive to do EWI properly.

as opposed to drylining where if you want to do it properly you need to lift floors, replace skirting, cut back ceilings, redecorate the room, and its still not continuous leaving thermal bridges.

As you say, may have to lift tiles and felt and replace.

last bungalow i did this was 700€ - worth it to avoid damp patches in the corner of the rooms & ceiling where wall plate/ end of rafters stops insulation overlap

I've seen it said elsewhere that EWI should extend down to the foundation. So need to dig out channel

or 500mm or so below ground. much of this prep & reinstatement works can be done by most DIY'ers

and potentially move drain pipes if downpipes go to ground too close to wall,

yes, but for example - you have to move curtain poles if you dryline

Also read that you may need to replace facia/soffit

typically they can be altered and reused

and possibly even extend out roof gutters

yes but only in a limited number of cases.

All this adds to the cost.

yes it does

Makes me wonder if it's economically worth it. I.e. how much will it reduce my heating bills by, and how many years of heating bills do I need to break even? Just not sure if it stacks up.

you would need to assess this as part of an overall fabric and heating assessment. what is your heating bill per year?

Added to that is the risk that the lay person (e.g. me) does not know enough about this to even be able to distinguish the true professional from the cowboy or even well-meaning amateur.

the same issue as with drylining unfortunately.

It seems that the risk is too high that a installer is chosen who does a sub-optimal job, resulting in minimal heat bill savings, and potentially even causing damage due to damp/mould build up in thermal bridges that were not considered.

thermal bridging is more of an issue with drylining.

Don't get me wrong, I'm knocking EWI per se. In fact, I would really like to get it done to two of the four walls on my house. But I'm finding it hard to justify the cost and risk.

what is the cost over and above drylining and decorating costs?

Ush1

I would have went for EWI had I not been completely redecorating the interior of my house from top to bottom. I just found it easier and cheaper, as I was tearing down the plasterboards anyway, to internally insulate.

kennyb3

Just wondering if anybody would PM me the names of reputable companies - those you've dealt with. would be much appreciated. Based in Dublin.

chillit

i am just starting to research EWI for my cottage. I would appreciate any feedback about reliable and recommended suppliers. PM me if you cannot post names on this board

thanks in advance

Bullocks

chillit wrote: »

i am just starting to research EWI for my cottage. I would appreciate any feedback about reliable and recommended suppliers. PM me if you cannot post names on this board

thanks in advance

Where are you based ?

chillit

I'm in Cork

NickSantigo

chillit wrote: »

I'm in Cork

Sorry to bring up this old thread but do you mind Pm me the crowd you used for EWI in Cork and if you were happy you went with it