Thread: Treating wood rot(again)

Looking at the pic this is a sliding sash with weights and you have taken out the cover that hides the weights?

You have Wet rot, so you just need to stop the water source and the timber will dry out naturally, the rot will not spread without moisture, once no moisture you have the rot under control, then takeaway the areas effected by the Wet rod and splice in new timber.

Always best to remove rotten timber than use some chemical hardener.

Originally Posted by Camelot

Looking at the pic this is a sliding sash with weights and you have taken out the cover that hides the weights?

You have Wet rot, so you just need to stop the water source and the timber will dry out naturally, the rot will not spread without moisture, once no moisture you have the rot under control, then takeaway the areas effected by the Wet rod and splice in new timber.

Always best to remove rotten timber than use some chemical hardener.

Yes I have removed the weight covers in the photo.
The problem is that our house is at 500 metres altitude, and escaping moist winters is not possible. The window is on the non-weather side of the house so thats one thing going for it. I'm thinking of making up a small galvanised steel shade screen to cover the sill and the brickwork it sits on so that it doesn't become a reservoir constantly feeding the rot.

25 years ago when I did the initial renovation, I had the window frame out before the internal walls were plastered, and at that point I had the wit to put some plastic damp course beneath the frame. What I have found really surprising is that there are a number of 8mm holes eaten through that plastic, which can only have been the rot chomping away at it. I would not have thought that possible, but there's no other way that it could end up looking like Swiss cheese.

This time I'm going to use an aluminium flashing sandwiched between two plastic damp courses.

I'm going down today to get a 5 litre container of Boracol 200 to brush and inject into the advance areas of the remaining timber to make sure I kill anything left. Going to cost me $70 but given I'm doing it all myself, peanuts compared to paying someone to do it for me.

Well I went out today and paid $77 for 5 litre container of Boracol200, apparently used by a lot of specialist restorers the sales manager told me, being their main customers. I'll be lucky to use more than 50ml of the 5 litres, but it seems pretty clear that there is bugger all around that is an effective solution to killing wood rot.

Here's hoping. It'll probably cause scorched earth for 10km down stream and wipe out the blue spotted koala and whale populations, but I'm at a point where I just want this rot dead, and $77 might just be what it takes.

When you put the DPC below your frame did you introduce weep holes? Rising damp does not climb above 1meter because of the weight of the water content, so if your house was built without a DPC at 150mm above external ground level then rising damp could reach your window sill height. However putting a DPC below your window sill while protecting your frame from rising damp may cause an area for rain water to sit (should it get in there), and then your timber frame will soak up the water, to try and prevent this, weep holes are added.

Originally Posted by Camelot

When you put the DPC below your frame did you introduce weep holes? Rising damp does not climb above 1meter because of the weight of the water content, so if your house was built without a DPC at 150mm above external ground level then rising damp could reach your window sill height. However putting a DPC below your window sill while protecting your frame from rising damp may cause an area for rain water to sit (should it get in there), and then your timber frame will soak up the water, to try and prevent this, weep holes are added.

My house was built in 1880, so no damp courses of any kind. When I bought the place in1985 it had sat empty for 30 years, had tree roots growing through the walls and across the lounge floor, one wall with a 10" outward lean, and no plumbing, electricity, windows, doors or floors. So I had the opportunity at that time to take the existing window frame out, fix it up, and built it back in, but with a single layer of standard 110mm wide brickwork dampcourse.

I didn't put the holes in, and due to its location beneath the frame, there was nothing that could have punctured it. The plastic in the holes is gone - something has consumed it! Mould is the only obvious possibility, one that likes plastic, something I would not have thought possible. The frame sits on a standard brick lintle, with a sloping mortar finish to direct rain outwards, but enough to constantly remain damp all winter. Hence my plan to put a shield there to stop the sill getting wet in the first place.

Originally Posted by jabell

I am repairing a 140 year old window frame where the cill had rotted out and it is slowly creeping up the sides. The wall was built around the window frame, making removal for repair not feasible without major work inside to cut out plaster and stonework surrounding it, so I'm doing the best I can with what I have. I have machined up a new western red cedar cill, and I'm still dreaming up some solutions for scarfing in some new timber to the sides. ...

Are you sure of that? It was not a standard construction method.

My house was built in 1882, same era as yours:

• cavity brick walls of sandstock (ie soft) bricks,
• one piece sandstone window cills,
• one piece sandstone window lintels,
• pine window frames and sashes.

Remember that the vertical window frame is a box section to hold the counter weights for the window sashes. The outside brick-work is half a brick longer than the inside brickwork and the box section sits in this vacant area. The entire window fram must be installed pre-made from the inside of the room, it is secured in place - nails or screws - then everything is hidden behind the architrave. If you remove the architrave then the installation should be fairly obvious. Hwere is a rough sketch:

Sash Windows.jpg


If you want to remove the window frame to work on it (probably advisable) then:

• Remove sashes - you will break the glass otherwise,
• Remove archtraves,
• Remove fastenings,
• Lift frame into room, then carry to workshop.

Its not difficult, but sounds daunting.

You missed the Parting Slip from your plan section which stops the weights from hitting each other, I have made a number of these Sliding Sash Windows for renovation/extension works to Victorian buildings and the sash was never fixed in place because of the weight box section not allowing a fixing to the vertical sides of the frame, so we only wedged them in place and then the splayed timber window reveals would stop them from moving. From the pic posted by the OP it looks like his house also has reveals rather than the brick and architrave detail that you have shown in your plan section.
Sash Window.JPG

Originally Posted by Camelot

You missed the Parting Slip from your plan section which stops the weights from hitting each other,

True; I tried to keep the drawing as simple as possible and omitted much detail including the divider, sheaves, trap-door, rebate in the sides, etc.

I have made a number of these Sliding Sash Windows for renovation/extension works to Victorian buildings and the sash was never fixed in place because of the weight box section not allowing a fixing to the vertical sides of the frame, so we only wedged them in place and then the splayed timber window reveals would stop them from moving.

Previous house, built in 1916, had wedged windows like you describe.

On current house, they window frames look like they have a reveal on the inside, but it is actually the window frame itself extending inside to the architrave and with a rebate extending from the interior beading. There are wooden plugs in the mortor between rows of bricks, and the frames are secured by nails through the "box frame" into those plugs of wood. Just three 4" nails each side - seems inadequate, but its lasted 140 years!

From the pic posted by the OP it looks like his house also has reveals rather than the brick and architrave detail that you have shown in your plan section. ...

Not sure that this is correct. Photo doesn't extend far enough.

Originally Posted by GraemeCook

True; I tried to keep the drawing as simple as possible and omitted much detail including the divider, sheaves, trap-door, rebate in the sides, etc.
Not sure that this is correct. Photo doesn't extend far enough.

viber_image_2022-03-29_12-35-39-984.jpg

Unfortunately the builders back in 1880 made no allowance for window removal. It is literally bricked in on 3 sides!
I would have to not only remove the architraves etc, but then cut out 100mm+ of brickwork/plaster from the two inside walls to get it out. Way more than I'm prepared to do now in an otherwise finished lounge room.
viber_image_2022-03-29_12-53-38-914.jpg This is why I'm having to come up with creative Plan B repairs and use an industrial grade wood rot treatment.
I have laid down an aluminium flashing underneath this time, plus a plastic damp course. New sill is Western Red Cedar I machined up out of a very nice chunk I retrieved from a demolition bin years ago, knowing there was some very nice timber in there somewhere. The joys of having a tungsten carbide spiral thicknesser!

Originally Posted by jabell

viber_image_2022-03-29_12-35-39-984.jpg

Unfortunately the builders back in 1880 made no allowance for window removal. It is literally bricked in on 3 sides!

I would have to not only remove the architraves etc, but then cut out 100mm+ of brickwork/plaster from the two inside walls to get it out. Way more than I'm prepared to do now in an otherwise finished lounge room. ...

Oh. This is very different from what I have seen. Please ignore my posts above as not relevent in this situation.