Installing my new sash windows...yum!

[Keycare]

My windows are ready!

A local joinery firm has created some breathtaking hardwood double-hung sash windows. The building is not listed and not in a conservation area so they had to comply with Building Regs. But they look superb. Solid brass fittings, real glazing bars for separate panes.

I didn't think I could get this excited about windows!

They are replacing some of the most hideous placcy windows I have ever seen, but it looks like I may have to tackle the job myself.

So do you fine and knowledgeable people have any tips for fitting them.

The house is rubble stone, it hasn't been pointed or rendered yet. It has brick-on-edge sills (which are cut in an ogee style). The internal reveals are splayed.

TTFN

Rich.

 

[biffvernon]

When I fit the windows that I make I don't use expanding foam or framing screws but just hold the new window firm with oak wedges hammered between masonry and the ends of the sills and lintels. Make sure the wedges only bear on the ends of the timbers or you will bend the frame. Then seal it all up with lime mortar. Thin cracks can be sealed with a mixture of linseed oil and very fine sand. Add oil to the sand and stir well until it has a stiff putty-like consistency. It sets hard after a few weeks but bonds tightly to the wood and remains flexible enough to accommodate seasonal movement of the wood.

 

[Keycare]

Excellent, the windows have been supplied with large over-cuts on both the sill and header, so I can use those extra bits as wedges when I cut them to size.

Would you use the linseed mixture for sealing between the base of the window and the brick sill or should I bed the window on something (lime mortar)?

I suspect you would shy away from any kind of sealant :shock:

Apologise in advance if that's a banned word.

 

[biffvernon]

Oh sealants are fine. They usually say things like 'Guaranteed for 10 years', so that should outlast uPVC.

You really want something impervious at the top of the brick below the timber sill. If there is no stone sill then insert a layer of slates or tiles or lead flashing or similar. It needs to have a slight slope so that any water that gets under the timber sill drains outwards and not down into the brick wall or in towards your cosy room.

Then stuff the crack with lime mortar if its big or linseed and sand if its a small gap.

 

[Penners]

Biff

hold the new window firm with oak wedges hammered between masonry and the ends of the sills and lintels

Is this the only physical fixing you use? Do you never get any problems from your wood wedges shrinking?

 

[biffvernon]

The lime mortar, inside and out, probably ends up good enough to fix a window by itself, but there's not much dimensional change in the length of a piece of timber and the wedges, dry when the go in, are hammered in hard. I suppose if something ever did work loose one could bash another wedge in.

 

[Gervase]

I find hardwood wedges more than enough to keep the window in place, even before the reveals have been plastered. Take care when hammering home the wedges, however, so that you don't distort the frames - it's easy to get a stuck sash if you're over-enthusiastic with the mallet. Try to keep the wedges nearer to the top and bottom of the frame and avoid the middle of the sides.
Before fitting I'd give all the wood that will eventually be hidden a good dollop of linseed oil, and certainly I'd prefer to bed the window on slate or lead if the sill is porous (as I imagine your bricks would be).

 

[biffvernon]

Try to keep the wedges nearer to the top and bottom of the frame and avoid the middle of the sides.

That's really important - don't just try -succeed. Make sure the wedge squeezes the end of sill/lintel/stile only or you will have a bent frame and windows that don't budge.

 

[skier-hughes]

Would you recommend this way of fitting for all window types Biff?

Graham