Sash Window Repair vs replace?

[jungle_jim01]

Hi, thanks to everyone who's been helping me with the damp...here's another little quandry...

...i've pulled out all of the mortar around the wooden sash window so that i can complete the repointing and replace the cement mortar around the frame with lime. Most of the wood is in ok condition and will just need to be stripped and treated, but the bottom 8 inches of the frame is pretty rotten on both sides. The question is...can i repair this or do i need to consider a replacement frame? Thanks in advance for your suggestions

 

[jungle_jim01]

looking online there's a lot of talk of repair...obviously this would be my preferred option...but this is a first for me so any tips etc on cutting out, makeing repair etc would be great.

 

[Moneypit]

From the English Heritage site -
Q. My wooden windows have a lot of rot in the frames: should I replace them?
A. The first course of action for windows in poor condition should be repair by an experienced joiner. Repair will not only improve the appearance of the window, it will extend its life and improve its thermal performance. Another option is to consider one of the two-part epoxy resin repair systems that can extend the life of historic windows. [end of quote]

There are a number of quite expensive two pack systems that are used professionally to carry out repairs for removed rotten timber. These seem to involve the fabrication of a mold around the affected area and injecting the mixed resin. Once hardened it can be sanded to the same profile as the timber section it has replaced. They must be available to the diyer, if thats what you are planning. On a smaller scale I have used car body filler, either cellulose or fiberglass, with good results. Obviously the important thing is to avoid further moisture attack to the remaining timber and it is how you choose to paint this that will have the biggest effect. I am a complete convert to the use of linseed paint. Yes it takes a long time to dry and more coats that any sane person would like to apply, but what a pleasure to use and you feel that you really are treating the wood instead of putting a water retaing skin onto it.

 

[jungle_jim01]

thanks...i'm all ready to go with the linseed paint...just need to sort out the rot. Making a mould sounds interesting. The frame isn't particularly intricate so i was thinking about making a wooden section to replace the rotten timber. Not sure which type of wood to use or how to attach though?

 

[Moneypit]

The sort of thing I mean is shown if you follow this link;
http://www.advancedrepair.com/architectural_epoxy/artssystem.htm

My view of splicing wood in is that it should be the same as what is being replaced. In old sash windows this usually means oak for the cill and a pine for the rest. However the quality of pine that you'll be able to buy is very questionable. You will probably be finding that where you are stripping the wood back, other than where it has rotted of course, it is as good as new and, compared to new wood, relatively hard. We have been lucky enough to be surrounded by neighbours who have fallen for the uPVC devil. If you are cheeky enough to ask for the removed wooden windows they make an excellent source of quality timber. In some cases, if the houses are of similar age/style then like us you can end up with a cellar full of old sashes, mostly complete with wavy old glass.

Good on you for going the linseed way

 

[Moneypit]

and this is the one I was thinking of;
http://www.repair-care.com/uk/default.asp

 

[jungle_jim01]

Thanks for that. The rot in my windows means that the bottom inch or so on each side has completely disintegrated...similar to how the 'red cross building' case study looks here: http://www.repair-care.com/uk/project_detail.asp?Id=1 It looks to me as though the gap has been replaced with wood then bonded with the epoxy?

 

[Delta]

Personally I would repair, and indeed have done so on four of our sashes so far. Well that's not strictly true, I have employed someone else far more competent to do it for me!

I did a small fixed window, replacing the bottom rail, but the sashes would take me too long and my dear lady objects to having windows boarded up for (what she says are) unreasonable amounts of time.

The four in need of TLC have all had sills replaced, and also the bottom of the sash boxes cut out new wood spliced in, varied from 2-16 inches. We have had some truly spectacular woodworm as well as rot. It did give me the opportunity to paint the sashes themselves, much easier when they are out. My nice joiner was quite happy to take them out and rebuild the boxes, then come back and re-fit the newly painted sashes later.

The sashes have all been very sound, a couple have needed gluing, one I added wedges and obviously putty repairs. All have scraped down well and painted look as good as new.

 

[agbagb]

Splicing new bits of the box lining shouldn't too difficult. Use "Redwood" from a timber merchant, not the "whitewood" from a DIY shed. (I've put together some info on buying timber). If you get picky you can find good dense heartwood and quite resious pieces.

The linings often rot at the bottom where they meet the cill because water doesn't drain from behind them. Put a notch at the bottom so the water can't collect.

Make sure you remove as much rotten wood as possible any soft bits left, give a good soaking of wood hardener. This gives a bounding surface for any adhesive (use PU glue) and for filler. I always get good results with epoxy wood filler, similar to car body filler but easier to chisel and sand.

If you have stripped the whole frame down then yes, Linseed paint is a great choice. Start with a coat of plain linseed oil first, warm it up or in full sun so it really soaks in and nourishes the old timber.

If youv'e not stipped it all back I'd just gone down the modern micropourus route.

 

[Penners]

agbagb - that's a very useful guide to timber that you've assembled. Just one small point - I'm surprised to see you specifying IV's for door framing. I haven't found anywhere that sorts IV's for some time - everyone seems to have got lazy (or cheeky) and chucks their IV's into the unsorted grade. So all I normally see is U/S, V's and VI's.

 

[jungle_jim01]

Thanks for the latest replies...really useful guide to wood. Unsure how to get hold of Redwood though....asked my local timber merchant and no luck...any suggestions?

 

[Me!]

Any timber merchant who knows nothing of redwood is not a timber merchant worth dealing with. Find another one who does know what you are talking about.

 

[biffvernon]

Yeah, that's a nice guide.

You do actually see redwood in B&Q but the last lot I bought was straight from a woodland. Larch, still growing. I could order the size I wanted because the timber still looked like trees. Of course the timber when it comes is wet so needs to be stacked in stick for as long as possible before use.

 

[agbagb]

Thanks Guys.
Penners, I think I'll Add a note/update on the grades available. It does seem to be getting harder to find well grades timber. PICK YOUR OWN, seems to be the answer because you can't trust their grading. I was hopeful it was just mylocal yards that were getting worse. I've seen "firewood" grade at the bottom U/S stacks.

Biffvern, I'm interested in you larch supply prices etc as I've got some ready for felling and I need to do my research. Could you let me know more?


Jungle jim, Appologies for side tracking. As ME! says, you need a proper timber merchant. Not so easy these these days, many aren't on the web so yellow pages might be idea.

 

[biffvernon]

Biffvern, I'm interested in you larch supply prices etc as I've got some ready for felling and I need to do my research. Could you let me know more?

Hard to say. A standing tree is worth a great deal less than a pile of swan planks. There's a lot of labour and machinery costs to take into account.

 

[JohnB]

Hard to say. A standing tree is worth a great deal less than a pile of swan planks. There's a lot of labour and machinery costs to take into account.

Doesn't the Queen get rather upset if you try to turn one of her swans into planks?

 

[biffvernon]

Hoy! Haven't you got a house to rebuild?