How to make a fitted window water tight

[GrantMcscott]

Hi

I have put in some of my windows with a tolerance around the frame.  I have been looking on the internet but not sure how to fill this gape now.   This is a timber frame house and the windows have fire stops around them. 

 

Is there a flashing kit or tape for the outside I can use

Should I just use expandable foam and sealants to the breather membrane 

 

With water Ingres and air tightness what is the correct way to do this

[Tennentslager]

A picture paints a thousand words Grant

[GrantMcscott]

1 hour ago, Tennentslager said:

A picture paints a thousand words Grant

Will take one tomorrow

[GrantMcscott]

Here are photos I need to seal the gaps after a sill has been fitted but was going to fill gaps left and right to make it a bit more water tight to the building wrap

 

What do do you use inside and out to do this properly so it is air tight and water proof

 

 

[ProDave]

Outside edge, compriband expanding foam.

 

Inside edge, tape to your building frame with air tightness tape.  If you are going for full air tightness you will be doing this anyway.

[Gone West]

My windows were fitted, by the suppliers, with a strip of Compriband around the centre of the frame. I then fitted another strip of Compriband around the outside edge and I foamed the inside edge with Soudal Low Expansion Flexifoam. I didn't use any airtightness tapes or membranes and achieved 0.47ACH.

[craig]

First picture you appear to be pretty tight to the frame, using the thin nozzle for the PU foam, might be a challenge to fill. I would try and squeeze in a 3 to 7mm expanding compriband and repeat on the right side on the inner and outer section of the frame but you might just be too tight.

 

You won't need anything else, no need for airtighness tape. I would PU foam the bottom and apply an airtightness tape here, you have got a large gap at the bottom. I would suggest compriband but it wouldn't be economical to do so. A single roll would be approx 5 to 8m length and you would waste about 4m of it, costing in excess of £100 for 1 roll.

Edited August 19, 2020 by craig

[Gone West]

I should have said before that Compriband is great but the only problem is that it expands very quickly when the weather is warm. When trying to squeeze the tape in between a window  opening and window frame it can be tricky. Also if the gap is larger than the tape is meant for, it may not be weathertight. There is a range of tape sizes for different gaps. If 3 to 7mm isn't thick enough there is 5 to 10mm or 7 to 12mm.

[Mr Punter]

Keep Compriband in the fridge if you are using it in warmer months.

[craig]

1 hour ago, PeterStarck said:

Also if the gap is larger than the tape is meant for, it may not be weathertight.

 

Just a fyi, a tape designed for 7 to 12mm gaps for example would give 900 pascals at 7mm and works for thermal insulation and acoustic insulation. 12mm the same but the pascal drops to 600. Past the 12mm you lose the gaurantee on weather tightness but would expand upto 21mm but ideally not past the tape width.

 

https://www.illbruck.com/en_GB/product/tp600-compriband-600/ technical data sheet, page 3 of PDF.

Edited August 19, 2020 by craig

[mvincentd]

16 hours ago, craig said:

A single roll would be approx 5 to 8m length and you would waste about 4m of it, costing in excess of £100 for 1 roll.

????

https://www.dortechdirect.co.uk/tremco-compriband-tp600-3mm-7mm-gap-size.html

 I have leftover Illbruck me501 tape for the internal (approx 10m left of the 25m roll) if you want it, pm me.

[craig]

Apololgies I meant to refer to ME508 membrane and would waste 24m of a 25m roll, TP600 15 28/40 would be 2.7m roll length and about £55 - wasting 1.7m length. Nice of you to offer the left over ME501 to him.

[Mr Punter]

The Illbruck / Compriband products seem like a crazy price.  Having seen some non-branded alternatives installed however, I would pay the extra money for the proper stuff, especially if it is installed in a location that will later be inaccessible .

[joth]

OP appears to be using Compriband inside a timber frame - this is interesting as our installers turned up with rolls of the stuff but refused to use it because the windows were being installed inside OSB boxes, where they said airtight tape and squirty foam is a better finish and that the Compriband only makes sense when the windows are installed directly into brick/block finish walls.  Any truth in that?

 

[markc]

Compriband is excellent for sealing against brick/blockwork and does work equally well against OSB, i reckon they just took the easy option

[craig]

 

1 hour ago, joth said:

where they said airtight tape and squirty foam is a better finish and that the Compriband only makes sense when the windows are installed directly into brick/block finish walls.  Any truth in that?

 

None what so ever. They have taken the easy option. Compriband does more than just seal a window, it has thermal, acoustic and weather tightness properties. 

[Ferdinand]

On 18/08/2020 at 19:04, GrantMcscott said:

Hi

I have put in some of my windows with a tolerance around the frame.  I have been looking on the internet but not sure how to fill this gape now.   This is a timber frame house and the windows have fire stops around them. 

 

Is there a flashing kit or tape for the outside I can use

Should I just use expandable foam and sealants to the breather membrane 

 

With water Ingres and air tightness what is the correct way to do this

 

One of our brethren from Bristol will be along in a minute to say that you need higher quality glass, and to offer to sell you some...

[joth]

1 hour ago, craig said:

 

 

None what so ever. They have taken the easy option. Compriband does more than just seal a window, it has thermal, acoustic and weather tightness properties. 

 

Thanks for confirming

I'm not in the least surprised, but at least know we're lapping EWI and render over the outside of the frame anyway which will go someway to mitigating this.

 

Still it feels  every single step of the process in ordering and installing windows comes with a massive side helping of disappointment.

 

[joth]

15 hours ago, craig said:

 

 

None what so ever. They have taken the easy option. Compriband does more than just seal a window, it has thermal, acoustic and weather tightness properties. 

 

Out of interest, do you have any source for this?

Ideally I'd like something that quantifies the improvements. Trying to understand if this is small marginal gains or a fundamental point any passivhaus should have insisted on

Cheers

 

[ToughButterCup]

14 hours ago, joth said:

.... 

Still it feels  every single step of the process in ordering and installing windows comes with a massive side helping of disappointment.

 

That's interesting. For us the process was fine. Line by line attention to detail is needed. 

I remember cold fear. That I'd get the dimensions wrong, that a window would be dropped, that one wouldn't fit, that the slider just wouldn't slide. The windows are our highest single item cost.

(Hmmmm, let's see about that... what might she manage to do with a German kitchen, eh? ) 

 

I must have treble checked the as built dimensions of the window openings three times. For the 4m slider, there was about 5mm clearance top and bottom, less either side.

BTW, I'm still finding good uses for the high quality packing timber, and almost every Torx screw used to hold the windows in transit.

 

Not that I'm mean or anything 

[craig]

2 hours ago, joth said:

 

Out of interest, do you have any source for this?

Ideally I'd like something that quantifies the improvements. Trying to understand if this is small marginal gains or a fundamental point any passivhaus should have insisted on

Cheers

 

 

https://www.illbruck.com/en_GB/products/innovations/i3-system/

 

Essentially an i3 application (3 layers) in a PH it's a given to be honest, it doesn't matter who supplies the products but it should be installed as standard. PU foam is not water tight it's an insulation layer. ME508 or equivalent is not water tight, it is an airtighness layer. So what weather tightness has been applied on the external aspect of the window frame? That's why compriband is used. It has thermal properties, it has weather tightness properties, it has acoustic properties and we all know the importance of thermal performance in a Passive House.

Edited August 21, 2020 by craig

[GrantMcscott]

4 minutes ago, craig said:

 

https://www.illbruck.com/en_GB/products/innovations/i3-system/

 

Essentially an i3 application (3 layers) in a PH it's a given to be honest, it doesn't matter who supplies the products but it should be installed as standard. PU foam is not water tight it's an insulation layer. ME508 or equivalent is not water tight, it is an airtighness layer. So what weather tightness has been applied on the external aspect of the window frame? 

Hi Craig

Nothing has been applied to the exterior to make it weather tight.  What would you recommend?

[craig]

1 minute ago, GrantMcscott said:

Hi Craig

Nothing has been applied to the exterior to make it weather tight.  What would you recommend?

 

Just by the pictures, you may not have the relevant gaps for a compriband. I would apply ME501 VV. I only recommend Illbruck, as it's what we use all the time and it does the job, I don't get anything from it.

 

https://www.illbruck.com/en_GB/product/me501-vv-duo-window-membrane-hd/

[joth]

4 hours ago, ToughButterCup said:

That's interesting. For us the process was fine. Line by line attention to detail is needed. 

 

I am of course being a bit melodramatic, I'm sure you'll agree everything seems so much more emotional when you're right in the thick of it.

Most of the frustration stems from having transferred responsibility for all expensive details to the main contractor I now have little control over those details, I'm the worst kind of back seat driver constantly trying to check the work and still mistakes happen that I get worked up about  

I'm conscious how vague I'm being. I'll do a full write up when I have the benefit and lucidity of hindsight.

 

Edited August 21, 2020 by joth

[joth]

3 hours ago, craig said:

 

Just by the pictures, you may not have the relevant gaps for a compriband. I would apply ME501 VV. I only recommend Illbruck, as it's what we use all the time and it does the job, I don't get anything from it.

 

https://www.illbruck.com/en_GB/product/me501-vv-duo-window-membrane-hd/

 

OK just had a chit chat with our contractor and they're already discussing something similar to this but using Iso Bloco (which I think gives back some of the acoustic and thermal benefits of the missing Compriband too)

Now I have the full picture, the reason to not use Compriband makes good sense to me: it would only have sealed the window to the OSB box it sits in, but the outside edge of the OSB box would remain exposed to the weather. Whereas the externally applied tape will join from the window frame right over the OSB box and onto the wall weathering layer, sealing the whole lot together.

 

Driver 1, backseat driver 0

 

(But still, I much prefer being an "informed consumer" than just tagging along for a rollercoaster ride)