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Retrofitting EWI


Onoff

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9 minutes ago, Ferdinand said:

As it is basically a cash grant up to X amount, if you choose to have a gold-plated solution at your own extra expense that is no skin off their nose unless your entire scheme falls within the limit, which probably means mid-terraces only, when it would be more complex. It will all be in the initial conversation.

 

That's good to know, although given our house is CW we'll not see a penny (unless Onoff and his fiendish and dangerous longtermist ideals infect innocent Government minds).

 

I couldn't even get them to fill the cavities on a Government scheme, so just paid for it myself. At least I got to choose the insulant that way (apparently on the schemes they tend to use fibre... I prefer EPS bead myself).

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1 hour ago, gravelld said:

I couldn't even get them to fill the cavities on a Government scheme, so just paid for it myself. At least I got to choose the insulant that way (apparently on the schemes they tend to use fibre... I prefer EPS bead myself).

 

You should have said, I've just binned a load...

 

2017-01-02_07-21-49

 

:D

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1 hour ago, gravelld said:

 

That's good to know, although given our house is CW we'll not see a penny (unless Onoff and his fiendish and dangerous longtermist ideals infect innocent Government minds).

 

I couldn't even get them to fill the cavities on a Government scheme, so just paid for it myself. At least I got to choose the insulant that way (apparently on the schemes they tend to use fibre... I prefer EPS bead myself).

 

 I had a loft done on a scheme 2 weeks ago and they were excellent. They took just an hour to add 250mm to the 60mm already there.

 

Turned out that the surveyor was a blues dancing acquaintance.


Ferdinand

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As I understand it, EWI should really continue below ground level for a certain distance. My understanding further is that it needs to sit against a"flat" wall rather than something rough with air pockets. In my case then the walls would need taking back and smoothing off with a render coat. The current finish looks to have been achieved by pressing a chip pan into the render! 

 

So.....when you get to the DPC,  a mixture of slate on some walls and a tarry substance elsewhere what happens there? Do you need that smooth rendered face to continue all the way "down"?

 

Then when you reach the footings, in my case not much wider than the wall:

 

20160824_124310

 

Do you stagger the EWI?

 

It's a right mess tbh. The render was continued down over the DPC. An external path had been laid on polythene sheet lapped UP the walls! Damp issues? Oh yes!

 

One step forward & two back! :)

 

 

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I have always understood bridging the DPC is a really bad idea.  Our previous house a 1930's semi when I bought it had "rising damp" problems with one section of wall in the living room being very wet. That was caused by the cement render bridging the DPC on the outside. On the surveyors recommendation, I cut back the render to just above DPC, formed a new bell cast at the bottom, and left the bricks below DPC exposed. That totally solved the damp problem.

 

I do still note some builders up here take the render over the DPC right down into the ground.

 

As for EWI going below ground, that does not to me sound like a smart idea. It would have to be some form of EWI that can stand being permanently wet, i.e. NOT wood fibre board.

 

A lot of LA houses up here are beinf upgraded with EWI. that stops at the original level (DPC level) and is being fitted to rendered walls, exactly like you are proposing.

 

I see nothing wrong with "air pockets" as long as there is no gap open to the outside, so a generous bead of sealant along the bottom edge to seal it as each EWI panel goes on perhaps?
 

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Cheers Dave. My thoughts were that if using EPS it could happily bridge the DPC without rising damp being a problem as it's not hygroscopic. This is I think why EPS is preferable to PIR all day long for EWI. 

 

Pretty sure it's done it's just the exact detail I'd like to know.

 

I once saw a commercial size stack of blue board insulation go up in flames on an adjacent site (think that was EPS). Thick, black, acrid smoke. It enveloped the site I was on and someone hit the alarm in our building. OUR stair pressurisation units kicked in sucking in thick, black, acrid smoke... :)

 

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10 minutes ago, ProDave said:

I would seriously try hacking back that render to just above DPC level (assuming you do have a DPC?) I'll bet it drastically improves your damp issued.
 

 

I have done so in parts along the wall, it's brutal on chisels!

 

If course you end up hacking the DPC level with the brick/block underneath so it really needs taking off above and a bell mouth reforming as you did.

Edited by Onoff
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So I have this nasty old,single glazed, wooden window in the downstairs cloak:

 

20170120_171834

 

I've measured up my existing window:

 

2017-01-20_05-32-11

Got a price from local guy of £160 all in (nephew's mate). That a for 28mm profile, 1.2W/m2K & includes handle/lock, sill and both top and bottom in Pilkington Stippolyte. He did offer and obscure Pilkington at no extra cost. I'm also having a wider sill for no extra as and when I do the wall in EWI.

 

Wickes nearest equivalent comes out at £135 and is a 24mm profile / 1.4W//m2K. I'm happy with the guy's price. Wickes also come with their trickle vents which I just think are noisy and draughty.

 

(I can get Compriband 600 for nothing for it which helps btw).

 

Now externally the existing window is fitted pretty much flush with the outside face:

 

20170120_172028

 

Knowing NOTHING ref EWI etc should I be fitting the new window inboard of where it is?

 

Tbh until I get the old window out I'm not sure of the construction. I only know when drilling thru for the outside tap recently there didn't appear to be a cavity.

 

Cheers

 

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12 minutes ago, Simplysimon said:

@Onoff i would have thought to keep the window where it is, if possible take some of the ingoes back a bit to enable you to wrap insulation onto window face. as i'm still learing about ewi and passive spec i could be wrong O.o

 

simon

 

Sorry, "ingoes"? 

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Just now, gravelld said:

Best (better?) practice would be to change the window when you do the insulation, and install it in the insulation layer.

 

I would like to do the EWI when and if we are able to get PP to change the hip ends on the bungalow to gables. Figure the EWI could just carry straight on up. As for getting PP I'm doubtful. The house has already I believe had it's 50% extension allowance before we bought it and I think if you increase the m3 in the loft by doing gables from hips that comes into it. Plus the profile that would change faces the road. That being said, looking up and down the road I would say gable ended properties outnumber hipped roofs by a big majority. AONB, SSI etc.

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31 minutes ago, gravelld said:

Best (better?) practice would be to change the window when you do the insulation, and install it in the insulation layer.

 

I've Googled "fitting window to EWI" looking for a section through view to no avail. 

 

Collecting the new Window next Friday

Edited by Onoff
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6 minutes ago, Simplysimon said:

it's all about minimising cold bridging, stopping condensation and mould growth, esp in a bathroom. the middle top and bot is the same detail with different views

 

simon

 

Appreciate the plan/side view thing! 

 

Do you have a link to the site, the quality of the screen grab isn't that easy to decipher?

 

Cheers

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One thing leads to another.....

 

In the back of future EWI considerations I'm seriously considering bringing my soils "inside". Currently have this:

 

SAM_4277

 

Ignore the brown soil going from the 3" down pipe temporarily.

 

As I'm now likely going to form a full height angled face in this corner to mount the shower controls I'm thinking maybe to move the vertical soil pipe above, inside into the corner then down under the footings? A bit more work but a much cleaner external result.

 

SAM_4286

 

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One thing leads to another.....

 

In the back of future EWI considerations I'm seriously considering bringing my soils "inside". Currently have this:

 

SAM_4277

 

Ignore the brown soil going from the 3" down pipe temporarily.

 

As I'm now likely going to form a full height angled face in this corner to mount the shower controls I'm thinking maybe to move the vertical soil pipe above, inside into the corner then down under the footings? A bit more work but a much cleaner external result.

 

SAM_4286

 

I'd need to mod the corner studwork.  Then core drill down through the ring beam I cast just about where the rake handle is:

 

SAM_1086

 

Which was covered in EPS:

 

SAM_1121

 

And of course the PIR and DPM!

 

SAM_1885

 

PPPPPP! :)

Edited by Onoff
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