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Measuring up for replacement windows


Crofter

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I've put in two new build windows, two replacement windows and 3 doors, all upvc. The windows were new and the doors all secondhand.

 

Limited experience then but I'd go for Compriband or Illbrück equivalent tape every time over foam. If I had to use foam then Illbrück FM330 over anything else. 

 

I'd really urge you to watch White Gold about how not to fit "double glazing". It's on Netflix. 

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22 hours ago, Novice Becky said:

I think I'll go for 10mm all round (so 20mm on each dimension) as I want to use Compriband (or equivalent) and airtightness tape

 

Personally I allow 7.5mm on every side, so 15mm on the width and height. That gives enough tolerance if the brickwork or windows are a few mm out, while also allowing enough space for Compriband / foam.

 

I use Compriband on the outside then, when it's expanded, apply Illbrück FM330 foam from the inside (a small initial foaming to avoid displacing the Compriband). To do that you'd need to leaving a gap between the window and the paster wide enough to insert the nozzle of the foam gun.

 

Note that Compriband, if installed correctly, is rated water tight to 600 pascals - that's a wind speed of around 70mph. In the case of a timber frame I'd add a lead tray below the sill to divert any rain that gets past the Compriband to the outside.

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@CrofterReally encouraging to hear that your windows worked out. Recip saw noted - I've been wondering about how I'll get the old ones out! Once I've ordered there'll be no going back and I'll have 8 weeks to swot up on how to do it.

 
@Gone WestGood to hear that other people had a first time for installing windows. I'll make sure I have plenty of help - also need to find a friend with Netflix to watch White Gold suggested by @Onoff.
 
@Mike @nod I like how there's always more than one way to do anything on this forum and you have to use your own judgement. I'll have a final think through my fitting tolerance. Having seen other people's windows I'm not too scared now - I don't have rendering to deal with and I have a 1.5m steel ruler. Tremco and Illbruck products are very popular on this site so I'll go with them. I have FM330 if I need it - just need to practise getting the quantities right (been a little over-enthusiastic in the past!)
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1 hour ago, Mike said:

Note that Compriband, if installed correctly, is rated water tight to 600 pascals - that's a wind speed of around 70mph. In the case of a timber frame I'd add a lead tray below the sill to divert any rain that gets past the Compriband to the outside.

Thanks. This is really useful to know in case I do other windows (I did get a leak at the top of my expert fitted windows a few years ago) but once I've fitted these windows I'm having the failed CWI insulation sucked out and replaced with EPS beads and THEN I can finally convert the side passage into a sort of shed/store so I don't think water ingress will be an issue for me.

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On 23/02/2024 at 15:56, Novice Becky said:

Hope it's ok to pick up this old discussion or am I supposed to start a new one? I'm measuring for replacement windows and I've been putting it off as I can't find anyone to install only (I supply) ... looks like I'll have to learn how to DIY and rope in some friends. It's just two windows down the side of my 1960s bungalow (plus a composite front door - on another discussion). I replaced all the other windows 15 years ago.  I think I'm going for timber frame, triple glazed from Russell Timber. They're good value and look pretty similar to my other (expensive) windows.

 
QUESTION: when measuring do people take off 10mm all round, so subtract 20mm from both the height and width?
There's no rendering, just brick, so I've measured from brick-to-brick on the width and on the height I did from mortar under the brick at the top to the bottom of the sill (see photos). I'll use the smallest measurements.
 @nod sounds like you've done this lots. Any advice?
 
Or any recommendations of builders/window fitters near J9 of M25? FENSA installers won't do it. Local builder quoted £1750 to fit 2 small windows and a composite front door (I supply windows and compriband and air-tightness tape). Sounded a lot to me.
 
Thanks for helping

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Where are you based? I can recommend some installers that will install only for you (location dependent), if you’re stuck.

Edited by craig
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Dropped you a message with number for installer, he’ll help ya and it won’t be £1,750 👍
 

Have you ordered yet? Speak with him on measurements, I’d be lookibg for 5mm all around on a brick opening like you have tbh. That’s enough for a 3 to 5mm Compriband or a nice mastic bead. 

Edited by craig
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  • 6 months later...

Resurrecting an old thread but I am similarly looking for an installer for triple glazed windows that are supply only.

 

i have one quote for installation which is £4.8k. This is for fitting 44 m2 of Windows, the sills and cling filming them (not sure if this is necessary?)
 

no idea if this is good value or not, seems a lot to me!
 

@Novice Becky who did you use in the end?

 

@craig would you share your recommendation?

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M2 is irrelevant tbh, the size of units, access, equipment, labour all need to be taken into account.

 

£4.8k and 44m2 is open to interpretation, without all the relevant knowledge required, it’s a wild guess if fair or not.

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22 hours ago, craig said:

M2 is irrelevant tbh, the size of units, access, equipment, labour all need to be taken into account.

 

£4.8k and 44m2 is open to interpretation, without all the relevant knowledge required, it’s a wild guess if fair or not.

Fair enough. Do you have any other installers I could try to get a comparative quote from? Would prefer to have more than one and also one that’s recommended.

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On 22/09/2024 at 17:26, haythorn_1 said:

It’s an extension and renovation. So windows into new openings in the extension then a couple of replacement windows in the old building.


Ahh OK, sorry, only guy I could suggest will only tackle new builds now.

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Hi @haythorn_1, I got 2 timber windows (3G) and one insulated timber front door supply only from Russell Timber Tech. I measured them myself and they were all a perfect size. I was pleased with RTT.

The recommended installer was pretty shoddy. They were supposed to use the Illbruck i3 system supplied by me (Compriband - FM330 foam - ME508 airtight tape). It looked such a mess that I removed the ME508 in one corner to re-do and discovered that they hadn't used any FM330 foam in the gap. I ended up cleaning the glue off the frames, doing the foam and applying new ME508 tape myself.
On top of this, when they applied the Compriband they stretched it around the corners in one continuous run rather than cutting it at each corner. Even I know that's not the way to do it! Consequently I have gaps in the corners - some worse than others. The worst ones you could see daylight through the corners (if they'd bothered to do the foam I wouldn't have spotted this).
Also, they didn't check with me about the height of the threshold before cutting the Compacfoam. So the door is too low, not enough space for a door mat and there's a bigger gap at the top of the door. And I'm still waiting for the FENSA certificate. Grrrr.
 
I paid £1000 inc for two people to come one day (not more than 6 hours) and fit 2 windows (not huge) and one front door. They were very good at removing the old windows but I would NOT recommend them. The other quote I got was £1750 to install.
 
In hindsight I wish I'd not listened to the people who told me to leave it to the experts. If I could do it again I'd still measure myself and get timber frame windows from RTT (they seem just as good as my expensive 16 year old Rationel windows). I would then either pay for someone to come and remove the old windows/door and lift the new ones into place and level and fix to walls (with them/me applying Compriband before lifting into place, me deciding where in the cavity to locate them - ie. all building regs my responsibility). Or I would get a couple of friends to come and help me remove the old windows/door (I understand not easy if you've not done it before) and secure/lift into place the new joinery, hacking off plaster on the reveals etc. Lift new window to check fit and remove again. I would apply the Compriband correctly (and quickly) before finally lifting into place. I would also stick the ME508 to the side of the frame before lifting into place. I would then foam (FM330) and do the ME508 myself. I would obviously have to sort out Building Regs myself too which would cost me £304 in Surrey (for up to 20 windows).
 
For me it's not necessarily about saving money. It's about having the job done properly with minimal hassle. No point in having 3G windows if they're not installed airtight.
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On 23/09/2024 at 20:30, craig said:


Ahh OK, sorry, only guy I could suggest will only tackle new builds now.

Ah that’s a shame. Won’t do extensions either? I think we will end up with only 1 window being replaced in the old house then 14 in new openings in the extension.

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