Wooden window resoration

[jonty]

I am looking to repair various rotten window/door components in our Georgian home and am aware that the replacement wood should really be as compatible as possible with the original both in its moisture content and species. Can anybody provide any advice please on soft wood species that would be particularly suitable and that have good rot resistant qualities? I was wondering about boat skin Larch that is used in the traditional wooden boat building industry?

There seems to be a dearth of detailed written information on wooden window/door restoration for old buildings. I have found various publications with broad overviews of various aspects of historic building care and restoration but can anybody point to any books/papers providing more detailed guidance and methodology please?

 

[johnandrew]

Hi Jonty

I can't be of much direct help, I'm afraid. But Donhead have some great books, including this one on windows windows

SPAB may have some good leaflets too.

 

[Penners]

I think it's possible to get a bit over-concerned about this. Assuming the original window structure is in softwood, then if you carry out a well-executed repair in a good quality pine (try to buy unsorted grade, clear*), and you paint with linseed oil paint, then I'm confident that your repair will last the lifetime of the window.

And of course, "the lifetime of the window" can be extended almost indefinitely with good maintenance.



* Unsorted - despite its apparent suggestion of poor quality - is the best grade of pine. Clear simply means free from knots.

 

[JoceAndChris]

There are lots of threads on here Jonty - if you're interested. Do a search on "sill repair".

Here's something that a member posted that I found useful:

http://myweb.tiscali.co.uk/teewal/sashprob/index.html

Is it better to use antique pine? Dad said he thought it was better to use the old stuff, so that's what we used. I have a lot of old stuff kicking around, and usually you're only talking about little bits let in, so you don't need masses.

 

[Andrew Bodenham]

Penners has got it spot-on. For window repair work you need straight-grained knot-free wood which will have similar behavioural characteristics to the original timber. In practical terms this means Redwood or Douglas Fir. A good timber merchant will be able to show you a selection of pieces; aside from basic dimensional requirements you are looking for straight, clear, with densely packed growth rings. Ideally avoid the very centre or heart of the tree. If you can use thinner stock e.g. 27mm this is often of better quality than 50mm stock, and is less likely to have shrinkage cracking due to over-fast drying. Let your timber stock acclimatise to the situation where it will be used for a few weeks, so that you don't find it growing or shrinking unexpectedly.

Having got your timber you need to consider the reasons why the original material failed in the first place to see if you can improve on the design detailing. Repairing sash windows I've often found that the builder's love of nails is a cause of trouble - steel nails corrode, expand, split the wood, let in water = wet rot. I try to avoid using mechanical fasteners, relying on the excellent performance of modern glue. Where unavoidable use brass or stainless steel. Polyurethane glue is ideal for repair work, and if time is tight the 5 minute versions can be a great help. However, I think the slower setting glues give a better bond. Gorilla glue is one readily available brand; I like to use Paratan, or Balcotan for more serious stuff. For situations where pu glue is not appropriate I fall back on aliphatic resin glue like Titebond3, which is truly excellent.

As you rebuild your windows think about designing out water traps and minimising the amount of end-grain timber which is exposed to rain / creeping damp. If you can keep the water out, and provide an escape route for that which does get in you've more than half won the battle. After that it's just down to your joinery skills to make the repairs blend seamlessly in.

These pics show a bay window repair from a few years ago. Essentially the bottom 6 inches of the window was completely replaced.

 

[biffvernon]

Penners has got it spot-on. For window repair work you need straight-grained knot-free wood which will have similar behavioural characteristics to the original timber. In practical terms this means Redwood or Douglas Fir. A good timber merchant will be able to show you a selection of pieces; aside from basic dimensional requirements you are looking for straight, clear, with densely packed growth rings. Ideally avoid the very centre or heart of the tree.

Indeed, but there can be confusion over names. 'Redwood' might mean Californian Redwood and suchlike, the genus Sequoia, but to most timber merchants, 'redwood' means softwoods that look red coloured. This could be Sequoia but is more likely to be Douglas fir, larch, western red cedar or Scott's pine all of which are more durable than 'whitewoods', again with a clue to appearance in the name. The redwoods have chemicals in them that are fungicidal and bactericidal, but this effect is much greater in the red part of the wood, the heartwood, and not in the sapwood which is a paler colour. A big tree has, proportionately, a lot more heartwood than a young tree, but they are not so common as timber is often harvested at ~30 years. A lot of old window frame timber is Scott's pine, well let's call it Pinus sylvestris as it might not have been grown in Scotland. The best quality was grown in the northern parts of Scandinavia, the Baltic and Russia where it grew slowly with tight growth rings. See if you can count 30 rings to the inch in the best. (The best oak is fast grown - with widely spaced rings.)

I think if I was making stuff from softwood for external joinery I would ask for larch, Douglas or Scott's pine if it had tight rings and always look for boards with a high proportion of heartwood. (Actually I'd use oak!)

 

[piper]

Biff, I notice that you determinedly use "Scott's" pine still - in spite of several pedantic (but good-natured, of course) exchanges we had about two years ago. Who was this man Scott, who either owns all the pine, or gave his name to it? When a highly educated and extremely well-informed chap like yourself continues calling it this, instead of Scots Pine (the pine native to Scotland), which is what I always thought its name was, I begin to doubt my own knowledge. May we have a definitive ruling?
Otherwise - I'll just take this opportunity of telling everyone I'm still alive, and I still follow this forum with great interest, though I now try to avoid wasting so much of my time writing lengthy posts.
It's good to see that we have now got some really informative and useful threads - as well as stimulating debates. The forum was a bit dominated by interior decor for a time - a bit "Country Living" (apologies to Joce ), but now we're back with all the macho stuff about lime, joinery and linseed paint. On the subject of which, I didn't finish linseed painting our new extension and windows last year because we never had enough dry weather. It's lovely stuff, but the drying is a serious issue if you live where we do - but I'm hopeful I can complete it soon.
Andrew - I hope your sash windows are successful, I'll be in touch to come and see them!

 

[biffvernon]

Ah yes, Piper. But tell me this, why is it common to leave out the apostrophe in Scots Pine? Surely it should be Scotland's Pine or Scottish Pine? (Whoops, a double tt seems to have crept in there.) Or should it be the Pine of the Scotts, which might be written as Scotts' Pine? Or Scots' Pine.

The OED gives the double tt as an option in
scot(t)ice
Scot(t)icism
Scot(t)icize, -ise
and mandatory in
Scottie
Scottish

You can have fun finding common usage with Google Fight.

Where's Evelyn when you need her?

 

[Nigel Watts]

Scotch pine? Or is that a description of how the somewhat dishevelled ladies and gentlemen who hang out in the churchyard near my house feel most of the time?

 

[piper]

Ah yes, Piper. But tell me this, why is it common to leave out the apostrophe in Scots Pine? Surely it should be Scotland's Pine or Scottish Pine? (Whoops, a double tt seems to have crept in there.) Or should it be the Pine of the Scotts, which might be written as Scotts' Pine? Or Scots' Pine.

No apostrophe because the word is an adjective, not the possessive form of a proper noun. The tree doesn't belong either to one Scot or to many Scots, to Mr, Ms, or even Sir Walter Scott, or to the whole family of the Scotts, or even to the nation of Scotland. 'Scots', meaning Scottish, is of course just a different spelling for 'Scotch' - though many Scottish people (Scots) don't like the -ch spelling of the word, unless applied to whisky (or eggs? - pies too, come to think of it). The word is also used to mean the language of (mainly) Lowland Scotland, though I don't think the trees speak it. They may understand it though - if whispered gently while hugging them, or when apologising before cutting them down.

 

[Schoolmarm]

but now we're back with all the macho stuff about lime, joinery and linseed paint.

Since when were they macho subjects?

 

[piper]

Since when were they macho subjects?

Never, of course. I was being ironic, tongue firmly in cheek etc. making a contrast with the equally non-gender-specific topics of curtains and cushion covers. "Macho" is surely a word which is not often used entirely seriously?
If I was being serious, I would have used "masculine" or "manly" perhaps, and it would have been wrong and offensive to do so. I certainly don't think like that myself!

 

[worms]

Ah yes, Piper. But tell me this, why is it common to leave out the apostrophe in Scots Pine? Surely it should be Scotland's Pine or Scottish Pine? (Whoops, a double tt seems to have crept in there.) Or should it be the Pine of the Scotts, which might be written as Scotts' Pine? Or Scots' Pine.

No apostrophe because the word is an adjective, not the possessive form of a proper noun. The tree doesn't belong either to one Scot or to many Scots, to Mr, Ms, or even Sir Walter Scott, or to the whole family of the Scotts, or even to the nation of Scotland. 'Scots', meaning Scottish, is of course just a different spelling for 'Scotch' - though many Scottish people (Scots) don't like the -ch spelling of the word, unless applied to whisky (or eggs? - pies too, come to think of it). The word is also used to mean the language of (mainly) Lowland Scotland, though I don't think the trees speak it. They may understand it though - if whispered gently while hugging them, or when apologising before cutting them down.

So the five pine trees in my garden can all be described as Scots pines (by location) or Scot's pines (by ownership) even though two of them are not Pinus sylvestris but actually Pinus nigra?!

 

[lou]

Biff, you said that the best oak is fast grown - with widely spaced rings. What does 'best' mean here?

 

[Schoolmarm]

Since when were they macho subjects?

Never, of course. I was being ironic, tongue firmly in cheek etc. making a contrast with the equally non-gender-specific topics of curtains and cushion covers. "Macho" is surely a word which is not often used entirely seriously?
If I was being serious, I would have used "masculine" or "manly" perhaps, and it would have been wrong and offensive to do so. I certainly don't think like that myself!

I would use that word entirely seriously to insult a man who thought he was 'ard as nails. Or wore those vests to show off muscly arms. Or a male chauvinist pig.


So I didn't see and still don't see any irony. :lol:

 

[biffvernon]

That's a tricky one, Lou. I think it has been determined that, all other things being equal, which they often aren't, that quicker grown oak with wide spaced rings is stronger. Of course best is not always the same as strongest - you might, for example, want something all knots and cats-paws, a pippy oak, because it looks pretty, but I wouldn't use that for a window frame - just the boards.

 

[Penners]

So the five pine trees in my garden can all be described as Scots pines (by location) or Scot's pines (by ownership) even though two of them are not Pinus sylvestris but actually Pinus nigra?!

No (as well you know, worms, you stirrer! :wink: ).

Scots Pine is Pinus Sylvestris. European Black Pine is Pinus Nigra.

Confusingly, much of the pine referred to as Baltic Pine or Scandinavian Redwood is, in fact, Scots Pine.

I suspect that your trees may be Pinus Ultima Thulis, which is known to grow in the coldest temperatures on earth. Unfortunately, when brought south to more civilised latitudes, it melts.

 

[biffvernon]

However, Wikipedia says:

The name derives from Latin pinus via French pin (pine); in the past (pre-18th century) this species was more often known as "Scots Fir" or "Scotch Fir" (from Danish fyr), but "fir" is restricted to Abies and Pseudotsuga in modern English.
Other names sometimes used include Riga Pine and Norway Pine, and Mongolian Pine for var. mongolica. "Scotch Pine" is another variant of the common name, used mostly in North America[20].
The timber from it is also called red deal or yellow deal.

http://en.wikipedia.org/wiki/Scots_Pine

 

[Schoolmarm]

Stirrer :lol: :lol: :lol:

 

[LadyArowana]

Never mind the wood, or what the tree is called, it's how big the cones are that is the important !