conservatory window sill replacement

[serval]

Ive got a rotten window sill on the top section of a conservatory that i need to replace.

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Is anyone able to tell from the photos what type of wood this is and what i should be replacing it with? hardwood or softwood, anything specific?


What's the best way to remove the old sill?
not sure how its fixed in place but I think the rotted parts will come out easily out because the wood is spongy.
I planned on cutting the rest out with a multi tool

once the sill is out what's the best way to ensure the surrounding wood is fully dry before treating with a suitable hardener and preserver? (ive got it covered with a tarp at the moment to keep it out of any rain)

When it comes to refitting the new sill ill be fitting it into the gap from where the old one was removed so i guess it will be hard to nail/screw it in ( i can see any obvious fixing points)
What other methods can i use to fix it in place? (adhesives/sealants etc)

[Job and Knock]

Is anyone able to tell from the photos what type of wood this is and what i should be replacing it with? hardwood or softwood, anything specific?

A bit difficult to tell, but basically if the timber is creamy or yellowy it'll be softwood whereas if it's lose-grained, reddy brown to yellowy brown it'll probably be an African or Far Eastern (tropical) hardwood. Without better photos it's not possible for me to tell. For replacement I'd certainly go for a durable tropical hardwood.

What's the best way to remove the old sill?
not sure how its fixed in place but I think the rotted parts will come out easily out because the wood is spongy.

Remove the glazing beads using a chisel and small pry bar (they should be pinned in place, but they may stick to the glass, and crack it, especially if the timber has been re-sealed/treated several times), then cut it out. I'd use a hand saw for the heavy stuff and only resort to the multi-tool when absolutely necessary as they are slow, noisy, have limited depth of cut and the blades (even cheap ones) are expensive

once the sill is out what's the best way to ensure the surrounding wood is fully dry before treating with a suitable hardener and preserver?

Check for punky wood using a flat-bladed screwdriver which will push easily into rotten stuff. I tend to chop it out with an old chisel. When you have gotten most of it out the last odd bits can be removed with a wire brush. Then the timber should be treated with a couple of coats of wood hardener (Bonda is excellent stuff and widely available from timber yards and builders merchants). Use an old/cheap brush as it will ruin any brush used with it

When it comes to refitting the new sill ill be fitting it into the gap from where the old one was removed so i guess it will be hard to nail/screw it in ( i can see any obvious fixing points)
What other methods can i use to fix it in place? (adhesives/sealants etc)

You will need to find some way to mechanically fix the repair/patch piece(s) to the existing woodwork. This may involve using an appropriate drill/countersink at an angle and long screws as adhesives or sealants alone are rarely sufficient

[serval]

What's the best way to remove the old sill?
not sure how its fixed in place but I think the rotted parts will come out easily out because the wood is spongy.

Remove the glazing beads using a chisel and small pry bar (they should be pinned in place, but they may stick to the glass, and crack it, especially if the timber has been re-sealed/treated several times), then cut it out. I'd use a hand saw for the heavy stuff and only resort to the multi-tool when absolutely necessary as they are slow, noisy, have limited depth of cut and the blades (even cheap ones) are expensive

once the sill is out what's the best way to ensure the surrounding wood is fully dry before treating with a suitable hardener and preserver?

Check for punky wood using a flat-bladed screwdriver which will push easily into rotten stuff. I tend to chop it out with an old chisel. When you have gotten most of it out the last odd bits can be removed with a wire brush. Then the timber should be treated with a couple of coats of wood hardener (Bonda is excellent stuff and widely available from timber yards and builders merchants). Use an old/cheap brush as it will ruin any brush used with it

Thanks for the advice J&K.

removed one window for a better look and ive dug out a substantial amount of rotten material and dried with a heat gun as can be seen.

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Ive probably lost too much material for it to be feasible to patch up with hardener and filler. The rot does not got right the way through the sill but the sill flexes up and down with not much pressure.

the sill is a singular piece that the vertical bars and end roof beam and roof panel sits on.... I reckon id have to dismantle all of the above to get the entire sill out and refit as a single piece.

Its only really the part that sits on the exterior that's really badly damaged.

What Im thinking is to chop the sill off with a vertical downwards cut along the line where ive marked in red.
Wood hardener and a bit of filler on the remaining material then screw in a new hard wood sill, using a bit more filler to make good any imperfections and joins.

Does that sound like a reasonable approach?