advertisement


Cracking to bay window after double glazing

I'm thinking of replacing a total of four large bay windows in two houses, both about 100 years old. I've bought lots of double glazing in the past but never a bay. I must say, when I saw this thread I went eek. So I'm keen to learn what I have to do to avoid getting into the same dire straits.
 
I'm thinking of replacing a total of four large bay windows in two houses, both about 100 years old. I've bought lots of double glazing in the past but never a bay. I must say, when I saw this thread I went eek. So I'm keen to learn what I have to do to avoid getting into the same dire straits.

Bays, built before modern building control regulations, are a potential structural disaster in the making. The exception being bays made of stone mullions with wooden casements inserted- but even here it is not uncommon to see stone or brick lintels deforming. If your bays are currently in good shape then you should ask any potential installer to explain how they intend to keep them that way and take lots of photos from various angles before work commences. Try and work out how your bay works, my one has ground floor sash window casements sitting on a cavity brick wall. Sitting directly on top of the sash framework is a solid brick wall with the first floor sash window sitting on top of that. On top of all that is the apex timberwork with some slates and two lead gulleys for good measure. Listen for suggestions or descriptions of vertical and diagonal propping when the ground floor gets removed. The first floor and higher are less crucial.
 
I'm thinking of replacing a total of four large bay windows in two houses, both about 100 years old. I've bought lots of double glazing in the past but never a bay. I must say, when I saw this thread I went eek. So I'm keen to learn what I have to do to avoid getting into the same dire straits.

yes wish we had had this thread before I embarked on this project !!!! i let the installers do a couple of jobs before i let them loose but i seem to have come unstuck !!!
 
I must say that the popular 1930s-style bay windows using only timber frames to support a wall above never struck me as the best idea ever. Especially a brick wall above. Daft. One of those things where the old builders didn't do a better job.

It may be for the OP that stronger load-bearing bay poles were needed downstairs to support the weight above. Have bay poles here to support a 30s brick wall/render above. Even then, caused cosmetic cracks here when installed many years ago as the old dodgy brickwork and mortar by the original 1930s dodgy builders didn't take too kindly to the upheaval of ripping out the old frames by the dodgy window installer.

Aren't double gazing window companies meant to be all regulated these days? I would have thought should be some comeback if they were installed incorrectly.
 
A lot of bays don’t have much in the way of foundations either.

Even single storey bays run into trouble. I know a road nearby where the 1900-era terraces have almost all had their single storey bays windows replaced with uPVC. Almost all have suffered the same fate…the brick arches over the windows have “dropped” and need re-doing.
 
Not sure if this will help but we had our windows replaced 15 years ago - 1930's bungalow with 2 curved front bays made up of 5 panels in each.

The bay poles they installed vertically inbetween each panel resembled scaffold tubes coated in UPVC. They were quite heavy duty. Like bespoke acrow props.
 
I must say that the popular 1930s-style bay windows using only timber frames to support a wall above never struck me as the best idea ever. Especially a brick wall above. Daft. One of those things where the old builders didn't do a better job.

It may be for the OP that stronger load-bearing bay poles were needed downstairs to support the weight above. Have bay poles here to support a 30s brick wall/render above. Even then, caused cosmetic cracks here when installed many years ago as the old dodgy brickwork and mortar by the original 1930s dodgy builders didn't take too kindly to the upheaval of ripping out the old frames by the dodgy window installer.

Aren't double gazing window companies meant to be all regulated these days? I would have thought should be some comeback if they were installed incorrectly.

yes they emailed me about 9.30 and said 2 of them were coming wed to look at what to do

cant get a structural surveyer till 10th november so might hang fire oon that !!
 
Discussions like this are why I don't believe the "old houses are better quality" opinions , and why I bought a house built in 1989. No sagging on that, it has Catnic steel lintels holding the window apertures up.
 
Discussions like this are why I don't believe the "old houses are better quality" opinions , and why I bought a house built in 1989. No sagging on that, it has Catnic steel lintels holding the window apertures up.

The thing about old houses is you have survivor bias - the only ones still about are the ones that weren't totally rubbish. I'm pretty happy with our old house, but i've also spent plenty of money on it doing the obvious replacements to worn out stuff, and since it's all bits of wood and plaster and brick, it's pretty easy to understand what is necessary. Your 1989 house is probably mainly held together with products extruded from sealant guns, and plastic pipework kept watertight with rubber seals :)
 
1930's garden city home here and it still has the original lath and plaster on the ceilings (with horse hair included)

The walls are built from Arlesey Whites (like little storage heater bricks) and it's a very warm and non damp house. We love it.

Owned 6 other houses prior to this, including a number of new builds, and this is the best built of them all.

I wouldn't buy a modern house if you paid me.
 
The thing about old houses is you have survivor bias - the only ones still about are the ones that weren't totally rubbish. I'm pretty happy with our old house, but i've also spent plenty of money on it doing the obvious replacements to worn out stuff, and since it's all bits of wood and plaster and brick, it's pretty easy to understand what is necessary. Your 1989 house is probably mainly held together with products extruded from sealant guns, and plastic pipework kept watertight with rubber seals :)
It's still mostly wood, plaster and brick. The different is the standard of engineering. There have been a few developments, after all. I'll take push fit pipework over solder joints, a working DPC and PVC guttering that I can ignore over rotten leaking wooden gutters, water ingress and rotting joists. My joists will outlast me, and require less maintenance (sadly).
 
2 days ago had a call from a friend , they had roofers in and house flooded after the work . they lost 4 rooms and had to move out . they now need a rental for some months , back in feb i helped a chap sell his house that was severely damaged by flooding from cowboy builders . both old houses . modern houses dont have the amazing stained glass this last place had !
 
Talking of bay windows, it's very windy here today, and i've noticed there's a draft blowing in between the skirting board and the floor of our bedroom, in the bay window. The bay has hanging tiles on the outside, so i've no idea what's behind these, but apparently there is a way into the wall cavity, which is then blowing out into the room. Oddly there's a hole through the floor for pipes to the radiator, and i can't detect the draft blowing up from under the floor, so it's maybe between the wall and the outer frame of the floor joists. Looks like i'll be having a bit of an investigation when the weather is better...
 
Talking of bay windows, it's very windy here today, and i've noticed there's a draft blowing in between the skirting board and the floor of our bedroom, in the bay window. The bay has hanging tiles on the outside, so i've no idea what's behind these, but apparently there is a way into the wall cavity, which is then blowing out into the room. Oddly there's a hole through the floor for pipes to the radiator, and i can't detect the draft blowing up from under the floor, so it's maybe between the wall and the outer frame of the floor joists. Looks like i'll be having a bit of an investigation when the weather is better...

A tiled bay window is probably just wood (like this). More chance for drafts, but probably a bit more sensible than balancing a brick wall on top of the window!
 
n.
A tiled bay window is probably just wood (like this). More chance for drafts, but probably a bit more sensible than balancing a brick wall on top of the window!

I've got a 1930s version of that, cold and flimsy so it was a real condensation trap until we put thick dry lining on.
 
I guess this is one advantage of 2"x4" (occasionally 2"x6") stud wall wooden homes that we have in the US - a single bottle jack can raise sagging walls / joists for shimming, or replacement of support columns. I think they're also warmer in the cold weather than brick.
Downsides - insect damage, regular repainting ($$$).
Hope the OP has a good outcome - problems like this would keep me up at night.
Over here old houses = great materials (wood) with some questionable designs. New house = better designs, but with worse materials (OSB sheathing).
 
Nor would I, but it's quite clever how they construct those roof voids with matchsticks !
Like I said earlier, they're engineered. Any fool can build a car for £100,000. To build one for £10,000 needs an engineer. In the same way, anyone can build a roof out of 8x3s.
 
n.

I've got a 1930s version of that, cold and flimsy so it was a real condensation trap until we put thick dry lining on.

Yeah, i've a feeling we missed a trick as we had the house scaffolded to repaint it over the summer. The house has cavity wall insulation, but it's unlikely to have a cavity or any insulation behind the hanging tiles now that I think about it, so I could probably have had the tiles off and done something about it. Oh well. We had the windows reglazed in thin double glazing units (into the existing frames) so as we resolve obvious places for heat loss the next worst offenders will bubble to the top.
 
I'd not worry too much ; such steady-state heat loss is proportional to the fabric area and the temperature drop across it (mitigated by its effective insulation value)

TBH - the most effective move anyone can make, of all, in a home- is always / has-always-been / draught-strips to windows, esp sashes, and external doors. And anything else you identify as a source of draughts. *

Regret on a on a missed chance to improve maybe 3sq.m by 0.5w/sq.m/degC delta T - is utterly trivial in comparison. It is differential pressure from prevailing wind that drives unwanted air exchange, and that is where the real excess heat loss occurs in most dwellings, to a very large degree. HTH.


*NB for any future searches here ! Do Not block any underfloor vent bricks to 'reduce draughts' in houses with joist & floor board ground floors - unless you want the ground floor timbers to rot out. Lay a membrane under your floor covering over floorboards instead. (in fact - never block such vents at all; they are placed there for many other reasons, even with conc ground floors)
 


advertisement


Back
Top