Screwing loose uPVC window to walls

[Oxbow16]

Hi

 

Hoping this is a simple one, but wanted to make sure I get it right.... Which is never guaranteed with me

 

There's a small uPVC window in my bathroom which is a little bit loose. The whole window (including frame) has movement within the opening.

 

Some of the other windows in the house have screws going through the frames and into the sides of the walls in the reveal. So I'm presuming I can do the same here to make it solid.

 

Does anyone have any tips as to what screws to use and how to go about it please?

 

Many thanks

[Marvin]

If the screws are going into the external wall then stainless steel.

 

See if you can squeeze some foam filler in any big gaps.

 

 Frame sealant between external wall and external edge of window frame. Inside same but use  caulking or what anyone else recommends.

[Onoff]

Loose? Could you get in round the edge with some low expansion foam to fill the gap? If you do foam keep the windows closed until it's gone off.

 

You might need to remove the glazing unit to drill and fix. To do that you have to remove the beads.

 

You can get a special tool but a sharp chisel will do it:

 

 

You can see a glazing bead removed here. Also the red packer between unit and frame. If you do remove the beads make note of where the packers are, photo etc, and which bead comes from where (pencil mark on bead and frame). When putting the beads back in put the short ones in first then the long ones as they'll bend more.

 

 

Once the unit is out you'll be able to drill through the frame into the wall and fit frame fixings. Not got a pic but you can see s fixing hole on the hinge side of this door. You basically drill an 8/10mm hole and bang in an 8/10mm frame fixing.

 

 

[Oxbow16]

Thanks guys - super quick and super helpful.  

 

The gap between window and wall on the inside is quite small actually.  I'd say less than 5mm for the most part.  So don't think expanding foam will be needed.  On the inside we'll be tiling right up to the window on all parts.  On the outside = good idea RE the sealant.  Actually, it's something I need to go round and do to all the windows when time allows.  Not entirely sure they all need it, but can't see it hurting and I'm a belts and braces kinda guy!  

 

As for access to the frame, really appreciate the above advice and pics but actually not needed on our window as it is a single openable piece and therefore all accessible.  Sorry, I should have said.  

 

Here's a couple of rubbish photos.  No light in there at the moment so had to use the flash in the dark.  

 

 

 

[Onoff]

Have a look here at what may be the reality of any DG window install. I found a horror story. No Compriband or expanding foam used, oversize gaps, all covered up with trim, superglued on. Basically draughty, cold bridges.

 

Your 5mm gap is a lot and you'll lose a lot of heat. 

 

 

[Marvin]

25 minutes ago, Onoff said:

No Compriband or expanding foam used, oversize gaps, all covered up with trim, superglued on. Basically draughty, cold bridges.

Yup! 5mm gap is enough to squirt foam in! Makes a hell of a difference. All Form. No Function!

Yuck!

[Oxbow16]

Thanks for the replies and the link too.  

 

So for gaps less than 5mm you would use expanding foam rather than sealant or caulk?  Just to be clear, in my case the gap is between the reveal and the front face of the frame, NOT between the side of the frame and the side of the wall as per the photos in the other thread.  

 

Ta

[Onoff]

Don't eff about with anything other than a proper foam gun and have a practice beforehand. This stuff is good but not in stock at SF unfortunately for some reason:

 

https://www.screwfix.com/p/soudal-soudafoam-expanding-foam-gun-grade-750ml/5026d

 

Be very careful using "foam". Aside from the mess, if you were to foam the gaps and leave the window open whilst it sets (and is still expanding), it can warp the frame and you won't be able to shut the windows. That's why I like the low expansion stuff. Another useful tip is lightly spray the gap with water from a plant sprayer. A damp surface takes the foam better.

 

Low tack masking tape around the frame to minimise foam getting on it.

[Oxbow16]

I've just been having a rummage and I found these... Are they concrete screws? Can you tell from a photo or any other way to tell if not?

 

Sorry to be such a DIY dunce!

 

 

[Onoff]

No they're not.

 

These are:

 

 

 

By frame fixings they usually mean these. You drill a hole the same diameter as the grey bit and knock in.

 

 

Bosch multi construction bits will drill through your uPVC frame and into the wall. This a 10mm one so you would use 10mm frame fixings.

 

https://www.ebay.co.uk/p/1004205987?iid=353457637942

 

 

[Oxbow16]

I can indeed see the difference, but then SF also sell these which they say are concrete screws which look similar to mine.  At least to my novice eye!  

 

https://www.screwfix.com/p/easydrive-countersunk-concrete-screws-6-x-100mm-100-pack/5537r

 

Not that I'm doubting anyone, just thinking allowed.  

 

Appreciate the replies, many thanks

[Onoff]

Unfortunately you're wrong! ? Yours are wood screws plain and simple. Concrete screws have a much "rougher", thread with extra thread forms so it bites. They also need a Torx bit to drive them rather than a Pozi bit like your screw. This reflects the extra torque required to drive them in and that you don't really want to be slipping when driving them!

 

PM me your address and I'll send you a sample. I think I only have 100mm long ones left though. 

 

Tbh I prefer (the grey) frame fixings for windows. If you hit a mortar joint with the concrete screws they'll likely just mince it up and not hold. 

[Oxbow16]

I don't mind being wrong, so long as I know I'm wrong and don't carry on regardless thinking I'm right!   So, thanks for putting me straight   

 

That's an extremely kind offer and hugely appreciated.  But I need to get some other bits form town so I've got them on the shopping list and will get them whilst out.  Thanks though - very thoughtful indeed.  

 

When it comes to sealing the gaps, what would be the downside of using a frame sealant instead of foam?  I've only used expanding foam once, and that was a few years ago.  I've heard the horror stories and I'm not always the best at being careful.  Frame sealant, caulk, etc, I've had a lot more experience with and am a lot more comfortable using.  Would it be a lot worse a choice?  

 

Also, you can see that black stuff sticking out in the pics above. Is that some kind of damp membrane? Presumably I cut that back to flush with the window (or a little proud to allow for the tiles). But when filling the gap, should the black stuff be against the frame or the wall? I presume the frame but thought best to check.

 

Many thanks

 

[Marvin]

22 hours ago, Oxbow16 said:

When it comes to sealing the gaps, what would be the downside of using a frame sealant instead of foam?  I've only used expanding foam once, and that was a few years ago.  I've heard the horror stories and I'm not always the best at being careful.  Frame sealant, caulk, etc, I've had a lot more experience with and am a lot more comfortable using.  Would it be a lot worse a choice?  

Foam in the gap.

Leave to dry.

Remove excess. on

The foam will shrink slowly unless covered so now is the time to put sealant on top!

The skill using the foam is to foam enough to join the window to the walls but not run it too much into the cavity. I try to run about 25mm on the sides and between the top and bottom of the frame fill any gaps.

 

Seal all 8 edges. Don't forget to seal under the cill where it meets the external wall!  

 

[Oxbow16]

Thanks @Marvin

 

32 minutes ago, Marvin said:

The skill using the foam is to foam enough to join the window to the walls but not run it too much into the cavity. I try to run about 25mm

 

I don't think I'll have trouble putting in enough to fill the window-wall gap, seeing as it is only 5mm wide!  Putting in too much is for more likely.  So I'll construct some kind of mock up with scrap wood so I can have a trial run first....

    

[craig]

Leave foam to dry if poss, makes a mess trying to clean when wet.

[Onoff]

2 hours ago, Oxbow16 said:

Thanks @Marvin

 

 

I don't think I'll have trouble putting in enough to fill the window-wall gap, seeing as it is only 5mm wide!  Putting in too much is for more likely.  So I'll construct some kind of mock up with scrap wood so I can have a trial run first....

    

 

The 5mm gap you can see might widen across the width of the frame. Whatever, 5mm will be like draught city at the same time as losing heat. Some window foaming fun here:

 

 

[Onoff]

Something I wrote in another thread. 

 

"Once the low expansion foam can is on the gun you leave it on until it is empty. You do not take the foam can off to clean in between uses unless you need to change foam types. You use the gun cleaner with the red nozzle on to clean excess, WET foam from around the nozzle (and anything you might get it on accidentally).

 

You undo the knob screw at the back of the gun to adjust the foam flow rate and squeeze the trigger. When finished for the day you turn the knob to close the valve and clean the end. Put it aside and pick up the next day or next week, month etc.

 

When the can is empty: Have an open plastic bag/bin liner ready. Have the gun cleaner at the ready with the red nozzle on. Unscrew the empty can quickly and put straight in the bin bag. Pick up the gun cleaner and use like an aerosol to spray up inside where the can screws on as some foam will be coming out there. Then screw the gun cleaner into the gun and give a blast thru pointing the nozzle into the bin liner. Remove the gun cleaner and screw on your new can of foam.

 

After you have used the gun then yes you can leave it upright with the foam can still screwed on, with the base of the can on the floor for however long you want within reason. 

 

Cleaning these guns doesn't mean a quick squirt through. Pretty sure the instructions say to put the gun cleaner on and leave for X minutes before blasting through finally. This is more for if you want to thoroughly clean the gun and store without a can on".

•  

[Oxbow16]

Thanks for the @Onoff - that guide will be very handy.  I'm all done with the frame fixings and no DIY disaster. My partner looked shocked!  I was more pleasantly surprised  

 

Will give some low expanding foam a blast around the window/wall over the weekend, with all your tips to hand.

 

On 16/11/2021 at 18:51, Oxbow16 said:

Also, you can see that black stuff sticking out in the pics above. Is that some kind of damp membrane? Presumably I cut that back to flush with the window (or a little proud to allow for the tiles). But when filling the gap, should the black stuff be against the frame or the wall? I presume the frame but thought best to check.

 

Does anyone have any thoughts on that before I do?  

 

Cheers

[Oxbow16]

I'm back from work now, and there was some loose wall in the reveal so I've pulled that out and taken another couple of photos which show the DPC deeper into the wall.  I thought they might better show what's going on and in turn what I need to do...

 

Cheers

 

 

 

 

[Onoff]

Were there wooden windows there before, that the uPVC windows replaced?

 

Have you got cavity walls? Two brick / block skins separated by a cavity. 

 

The ideal when fitting a replacement window is a 5mm gap all round but perhaps had to achieve in practice unless you DIY, chip bits of wall out to measure the old wooden frame exactly etc. A firm you get in won't go to the nth degree and likely allow a bit more. Or as you and I know a LOT more to make fitting easier. They won't give a sh!t you're left with draughty gaps forever. The ones that did some of my windows didn't even use foam. 

 

Tbh I'm not sure what I'm looking at there ref that black DPC. Yes, that's what it is, judging by the diamond pattern in it. Comes in rolls 100 - 200mm or more wide. 

 

Traditionally, wooden frame windows would be wrapped in a damp proof membrane to stop the frames getting damp and transferring damp/cold, from the outer to inner wall leaf (assuming a cavity).

 

Is it wrapped around the uPVC frames and just tucked over inside?

 

I've seen folk wrap a uPVC i.e  "plastic" window in more plastic before, insisting it "stops damp" ?

 

@craig is our resident window expert and can probably best advise what you might have there and the history of fitting.

 

[Oxbow16]

Morning Onoff

 

Not sure what was there before but I'd think wooden windows is most likely.  It's a mid-70s extension and the current windows - I think - were put in around the turn of the century.  

 

Yep, it is cavity walls.  

 

Hard to tell how much the DPC wraps around beyond what you can see in the photos.  Unless I take hammer and chisel to reveal, which I'd rather not!  I will have another look now it's daylight though, and also a look at other windows from the same era to see how they look.  

 

 

11 minutes ago, Onoff said:

The ideal when fitting a replacement window is a 5mm gap all round

 

We discussed me filling all gaps with expanding foam, even as small as 5mm.  Does that matter seeing as there is meant to be a 5mm gap (something I also read/saw on youtube vids earlier in the week)?  Presumably the gap is to allow the window to expand / contract?  Or is the idea that expanding foam is flexible enough to allow the expansion whilst eliminating the draughts and cold?  

 

Thanks again and have a great weekend.

[Onoff]

The 5mm gap is the gap to aid fitting. It MUST be filled otherwise it's just a route for the outside cold. The expanding foam has enough "give". 

 

You will need a proper foam gun and low expansion foam, gun cleaner etc. I'd also run some masking tape up the window before you do it.

 

The absolute ideal, professional method is to use an expanding foam tape like Coompriband before the window goes in. Around the outside of the window and cill is a channel. You stick this tape on only when you know the window fits and you have to be quick about it. The tape then expands from say 5mm thick to 25mm thick and seals between window and wall. 

 

Those in the know here actually go to the lengths of, in effect, applying airtight tape around their windows to where they meet the walls. 

 

It's all very well btw, sealing everything up but you must consider ventilation to. Have your windows got trickle vents fitted?

[Oxbow16]

That all makes sense RE the 5mm.  I was thinking about it properly.  

 

I did see expanding tape while I was looking into it earlier this week, and I wondered when and how that would be used.  That explains it then   

 

 

4 minutes ago, Onoff said:

It's all very well btw, sealing everything up but you must consider ventilation to. Have your windows got trickle vents fitted?

 

I do tend to struggle with the theory behind the sealing vs ventilating balance.  Think I might have done a thread about it a few months back.  It's something I need to get my head around as we do more work on the house.  As I sit here now only two coffees into the morning, I scratch my head when I think on the one hand the desire to seal around the window properly to eliminate all draughts, cold bridging etc, yet on the other hand the need for a trickle vent.  Or perhaps it's quite simple - the gaps around the window aren't controllable whereas the trickle vent is???  In any case, there's no trickle vent, but we do have the window open often-ish.  

 

Cheers

[craig]

5 hours ago, Onoff said:

@craig is our resident window expert and can probably best advise what you might have there and the history of fitting.

It’s for exactly the reason mentioned, vertical DPC is “usually” installed and used to stop water travelling sideways.

 

I’m not a fan of it, as that means if water is getting to the point the vertical DPC is stopping it travel sideways. Then it has to travel somewhere and just shifting the problem rather than preventing the problem (if a water issue exists).