Window Window Frames - Advice

[CarterSum]

Hi All,

Apologies if this has been covered before, I carried a quick search on the forum and couldn't really find anything related to my question.

We have recently moved into an Edwardian period house which has 2 original 7 splay casement bay windows. They haven't been looked after very well previously and while the tops of the frames and casement windows aren't too bad there are issues with where the water has collected at the bottom of them. We were looking at getting them restored after reading lots of positive comments about restoration as well as wanting to keep as many of the original features as possible but one of the glaziers that has come to quote for the job has suggested that it would be better to replace them as restoration will only be good for around 10 years.

He quoted us a price for Scandinavian Redwood frames and has said that these will last (if looked after appropriately) for 60+ years. With this in mind I tried to carry out a little research and have found a couple of different school of thoughts:

Some people have stated that they would never consider softwood and that I should only use hardwood.

Some people have said that softwood is fine if it is treated properly and in some cases is better than hardwood

I have also read that if you are to use softwood then don't use Scandinavian Redwood and use Douglas Fir as it is moderately resistant to decay and the redwood isn’t.

Would any of you have any thoughts on the above and what you would do in this situation? I am keen to do the right thing and want something that will last rather than have to revisit in a few years time.

Thanks

Carter

 

[murdoch]

Hi Carter,

As joiners we make loads of windows. The quality of redwood isn't that great on the whole, its ok to keep costs down but the quality is constantly getting lower.
We have used a lot of hardwood in the past (sapele, utile, idigbo ect) and this is much better and will last longer. The quality of hardwood is also lowering though and it does tend to be more prone to warping and slightly unpredictable.

We have switched to doug fir recently as suggested by our timber supplier. it is a similar price to hardwood but machines and paints better. its so much more stable and we rarely have to go back due to timber movement. its also extremely durable and our supplier has ensured us it will last much longer than hardwood.

No timber will last well however if the windows aren't well maintained and painted to stop water getting in on a regular basis.

On know that in our heads we're conditioned to think hardwood is better than softwood but doug fir is the bees knees.

 

[ColeyS1]

I'd say where windows are concerned the majority of the cost is down to labour. It'll take the same time to make it in softwood as it would in hardwood- might take a little longer when you factor in the extra 'brush treatment' that softwood benefits from. So if you were to say on a complex window that costs £1200 only £200 of that might be softwood, hardwood might cost an extra £300 so your complex hardwood window now costs £1500. 20 years time, you don't have to repay the labour all over again not to mention the making good redecorating etc.

My old work use to send off softwood for some type of clear pressure treating. They would pay me to pallet it up, then pay to have it taken and collected from the plant, then pay for it to be stacked so it could dry out, then finally pay for all the joints to be eased cause everything had swelled up and moved around. - I still struggle to see how it worked out cheaper than just using hardwood :?

Coley

Sent from my GT-I9300 using Tapatalk

 

[pmagowan]

All the sash windows on my house are softwood and have lasted roughly 80 years. I patched them up a few years ago and repainted them and am only replacing them now as part of a larger restoration where I am putting in 3G. So, from my experience, softwood can last well if maintained.

 

[blackrodd]

I'd say where windows are concerned the majority of the cost is down to labour. It'll take the same time to make it in softwood as it would in hardwood- might take a little longer when you factor in the extra 'brush treatment' that softwood benefits from. So if you were to say on a complex window that costs £1200 only £200 of that might be softwood, hardwood might cost an extra £300 so your complex hardwood window now costs £1500. 20 years time, you don't have to repay the labour all over again not to mention the making good redecorating etc.

My old work use to send off softwood for some type of clear pressure treating. They would pay me to pallet it up, then pay to have it taken and collected from the plant, then pay for it to be stacked so it could dry out, then finally pay for all the joints to be eased cause everything had swelled up and moved around. - I still struggle to see how it worked out cheaper than just using hardwood :?

Coley

Sent from my GT-I9300 using Tapatalk[/quote

A friend has just had some quotes for joinery, two windows and a door.
This joiner said that sapele would add about £20 to the material costs, as opposed to redwood on each item.
my personal opinion is that whilst douglas fir is better than red soft wood, my preference would be for iroko if it is still available. And do not use water based primer, never to be used on exterior work, it was designed for speed not quality. Dulux silver primer, good for any hardwood and oil based undercoat and gloss.
Douglas fir would be the closest equivalent to the excellent pitch pine is my second choice. HTH
Regards Rodders

 

[ColeyS1]

All the sash windows on my house are softwood and have lasted roughly 80 years. I patched them up a few years ago and repainted them and am only replacing them now as part of a larger restoration where I am putting in 3G. So, from my experience, softwood can last well if maintained.

Modern softwood isn't a touch on the old stuff

Coley

Sent from my GT-I9300 using Tapatalk

 

[heimlaga]

Scandinavian redwood is in fact the same species as Scot's pine. I'll just call it pine from here onwards.

Heartwood and sapwood are very different. The light yellow sapwood rots in a quarter of the time it takes for the reddish brown sap wood to rot. The slower it grows the better it gets. The best pine comes from a three with a straight trunk with few knots and a flat top growing in fairly dense forest on a dry northfacing hillslope away from the coast. Preferably as far north as possible.
Unfortunately the modern kind of forest management is strictly geared towards producing a lot of wood rapidly. Hence most woodlands are thinned too radically in order to speed up growth and then logged before the trees are mature. Therefore most wood sold today is knotty and has little heartwood in it.

The only two ways of getting proper wood for sashmaking are buying standing trees from a smallholder or buying from a small sawmill that specializes in high quality timber. Neither is avaiable to you down in the UK.

Up here all traditional window frames are made from pine. Even the delicate glazing bars. Traditionally only selected slow grown heartwood was used for the outer sash. The inner sash in a double sash window can be made from sapwood as it is protected from the weather.

Theese days a lot of pine sapwood is used everywhere and often the outer sash is pressure treated. Unfortunately the pressure treatment seems to tear the structure of the wood apart and decrease it's resistance to weathering so there isn't much gained from it.

From my experience 40-60 years is a fair life expectacy from an outer sash made from sapwood even with proper maintainence. Sometimes they may last only 30 years.
Outer sashes made from slow grown heartwood is a completely different matter. With proper maintainance I would expect one to last between 100 and 200 years but occasionally one may find sashes that are over 250 years old and still sound.

 

[richarnold]

Hi there.
as restoration joiners we have not used anything other than Accoya for the last four years now. This has solved all our problems for exterior joinery. There is nothing on the market that comes anywhere close to beating it. It comes with an unconditional 50 year guarantee, but I strongly suspect that anything made of it will still be here in 300 years!. I think they are already talking of putting up the time to 70 years. The timber doesn't seem to move at all, so its particularly good for sliding sashes.
By the way .I am in no way affiliated or connected to the Accoya business, I'm just really impressed with it, and think it's the best product on the market for exterior joinery. It's also great for the environment too.
This is there web site if you need more info http://www.accoya.com/.
Cheers, Richard.

 

[MMUK]

I've been using Douglas Fir for timber windows for a while now. If they are white, once built I have them powder coated. The powder coating is guaranteed for 25 years.

 

[pmagowan]

All the sash windows on my house are softwood and have lasted roughly 80 years. I patched them up a few years ago and repainted them and am only replacing them now as part of a larger restoration where I am putting in 3G. So, from my experience, softwood can last well if maintained.

Modern softwood isn't a touch on the old stuff

Coley

Sent from my GT-I9300 using Tapatalk

I think they made everything better in the old days! My first big woodworking project was a 28 foot mahogany boat. At 60 years old with some poor maintenance there was only a small amount if rot and we had quite a time finding similar quality timber for the repair. I think a lot of woods longevity comes from its quality but still a lot of it comes from maintenance.

 

[CarterSum]

Thanks for al of your responses. It seems that Douglas Fir may be a good way to go. I have asked the glazier to see if this is an option.

One last question is - if there is anything else that I should be asking? I didn't even think about asking what type of coating they were going to use!

 

[MMUK]

Ask about the locking system. Pretty much everything now should be shootbolt locking rather than the older and less secure espagnolette.

Also ask about the hinges. Regs state that each "habitable" room must have at least one fire escape opening so you'll need egress hinges. A habitable room inclues bedrooms, lounges, dining rooms, etc. but as a rule of thumb, I try to incorporate a fire escape vent into every room.

A fire escape, or egress, vent should be a minimum of 0.33m2 with minimum dimensions of 450mm in either direction and the base of the opening has to be a maximum of 1100mm from floor level.

Another note, a lot of installers will try to tell you that trickle vents are required by law - this is not the case and never has been, it's just become a "standard" in new build.

Finally, your installer should be registered with CERTASS or FENSA. If they're not, look elsewhere.

 

[CarterSum]

Ask about the locking system. Pretty much everything now should be shootbolt locking rather than the older and less secure espagnolette.

Also ask about the hinges. Regs state that each "habitable" room must have at least one fire escape opening so you'll need egress hinges. A habitable room inclues bedrooms, lounges, dining rooms, etc. but as a rule of thumb, I try to incorporate a fire escape vent into every room.

A fire escape, or egress, vent should be a minimum of 0.33m2 with minimum dimensions of 450mm in either direction and the base of the opening has to be a maximum of 1100mm from floor level.

Another note, a lot of installers will try to tell you that trickle vents are required by law - this is not the case and never has been, it's just become a "standard" in new build.

Finally, your installer should be registered with CERTASS or FENSA. If they're not, look elsewhere.

All good stuff that we haven't even considered thanks for the tips

 

[RobinBHM]

+1 Accoya

If you are changing from original single glazed casements, make sure you understand how the heavier sections of new dg windows will look. It is surprising how much the sightlines will changes, especially on mullions with a sash stile either side.

 

[meccarroll]

Hello, looking at the post I think it might be prudent to contact your local Planning Department (Via the local council) before you go ahead and make any alterations to your existing windows.

If you live in a conservation area or a listed building, restrictions may apply as to what work you can or can not do regarding your windows. It's worth making a check with your local planning department because if you alter windows on restricted buildings you may have to pay to have the new windows taken out and then pay to have the openings put back to their original state.

Repairs to windows can be very effective if the repair is carried out to a high standard by quality tradesmen. It's simply rubbish to say a repair will have a ten year life span, it depends on the quality of the repair the materials used and aftercare. If all of the rotten section is removed while doing the repair and replaced with new treated timber there is no reason why the repaired section should not last just as long as a new wood window.

Whatever happens obtain at least three quotes for your repairs/new windows so you have a fair idea of what is the going rate in your area.

Fensa and Certas registered installers are two options for the installation of your new windows if you want a degree of protection from the schemes involved. Or you can ask your local joiner to make and fit the windows for you, using your Local Council Building Control officer to certify the work, just ask the joiner to make the necessary arrangements in the price of the work. keep your options open and look around to give yourself as much choice as possible.

Good luck.

 

[Phil Pascoe]

Try to make sure the wood is treated after the joints have been cut, but before the the windows have been assembled - nearly all rot is in the joints.

 

[RossJarvis]

Try to make sure the wood is treated after the joints have been cut, but before the the windows have been assembled - nearly all rot is in the joints.

I'm not an expert, but it does seem to me that softwood frames often aren't made from pressure treated wood, why is this? Painted on treatment is nowhere near as good as pressure treatment. I can appreciate that not everyone can pressure treat wood, but why can't they use pre treated wood? Or does pressure treatment only go in so far and not get to where joints are likely to be made?

 

[G S Haydon]

Hi there.
as restoration joiners we have not used anything other than Accoya for the last four years now. This has solved all our problems for exterior joinery. There is nothing on the market that comes anywhere close to beating it. It comes with an unconditional 50 year guarantee, but I strongly suspect that anything made of it will still be here in 300 years!. I think they are already talking of putting up the time to 70 years. The timber doesn't seem to move at all, so its particularly good for sliding sashes.
By the way .I am in no way affiliated or connected to the Accoya business, I'm just really impressed with it, and think it's the best product on the market for exterior joinery. It's also great for the environment too.
This is there web site if you need more info http://www.accoya.com/.
Cheers, Richard.

Amen to that Richard. It is my favorite timber to use for painted joinery.

 

[Phil Pascoe]

Try to make sure the wood is treated after the joints have been cut, but before the the windows have been assembled - nearly all rot is in the joints.

I'm not an expert, but it does seem to me that softwood frames often aren't made from pressure treated wood, why is this? Painted on treatment is nowhere near as good as pressure treatment. I can appreciate that not everyone can pressure treat wood, but why can't they use pre treated wood? Or does pressure treatment only go in so far and not get to where joints are likely to be made?

If you cut a 4" x 2" that has been treated, you will see an eliptical portion in the centre that has not had any preservative penetration - that's the problem bit. I've just sold a house with a front gate that I made 20yrs ago - only spruce, but I soaked the individual pieces for two weeks before it was made - it is still perfect. Get your retaliation in first!!

 

[RossJarvis]

If you cut a 4" x 2" that has been treated, you will see an eliptical portion in the centre that has not had any preservative penetration - that's the problem bit. I've just sold a house with a front gate that I made 20yrs ago - only spruce, but I soaked the individual pieces for two weeks before it was made - it is still perfect. Get your retaliation in first!!

Aha! I've just found my garden composters have rotted out after five years, even though I "preserved them" with painted on treatment. It seems that this stuff is not much cop unless you soak the stuff in for a good time or use some form of pressure vessel. Plus pressure treatment seems to only work in so far.