On a timber frame house, should the window be attached to the frame,
span the cavity, or hang off the brickwork?

Also, I need at least a "100mm reveal" for conservation purposes, but
I'm getting different stories on what this means.

If the window is on the timber frame, should the bricks overlap the box
holding the weights and should they therefore bridge the cavity?

Any help would be greatly appreciated.

no content

cabiri.tech@gmail.com wrote:

> On a timber frame house, should the window be attached to the frame,
> span the cavity, or hang off the brickwork?
>
> Also, I need at least a "100mm reveal" for conservation purposes, but
> I'm getting different stories on what this means.
>
> If the window is on the timber frame, should the bricks overlap the box
> holding the weights and should they therefore bridge the cavity?
>

"reveal" means that part of the insides of a wall revealed when an
opening is constructed. So a hole in a 9" brick wall has a 9" reveal
etc. Your "100mm reveal" means that about a 100mm depth of masonry
should show infront of the window i.e. a brick thickness if it's a
brick wall. This is obviously impossible with a single brick wall such
as you might have in a timber framed building, so the front lining of
the window has to be flush with the external face of the wall - no
reveals at all. In a 9" wall a sash would normally be put in an
100/150mm rebate on the inside so that only the edge of the front
lining will show to the outside and the inside linings will be flush
wth the inside wall - the join covered by an architrave. In a thicker
wall there will also be reveals on the inside, often splayed.
Sash windows are later than timber frame buildings so don't always fit
easily not least because timber frame is often a composite of timber
and other masonry, nd often not straight.You could have one side
against timber and the other against the infill (brick etc) or other
variations. Have a look at whats already there.
Sashes are always fitted by sitting on a cill with spacers under each
corner such as bits of slate or glass and folding wedges at the top.
Old ones often really easy to remove - you just loosen the wedges at
the top corners and the whole thing falls into the room.
cheers
Jacob

You could go by the amount of space left over between the last rain
drip groove in the cill. Wooden ones have to hang over the brickwork by
a fair bit. Look to get some 30 mm give or take quarter of an inch on
the reveal between the uprights of the window and the outer edge of the
wall.

With a timber frame they may have supplied enough bits of mdf or
whatever to form the cavity closers. These may be 1/2 or less. Get some
decent stuff, 3/4 of an inch thick or so, as any draught in the cavity
will cool the areas around your windows.