Rotten Sill **Now with Pics**

[dirtydeeds]

here is a picture of a stile cut out and cill repair done last year

[dirtydeeds]

this sash was only about 30 years old

the picture gives some idea of the work you need to carry out




i dont have pictures of the method.

[royclarke]

The brickwork

[dirtydeeds]

the house was built in 1889

the bricks are semi soft reds on the most exposed elevation of the house

the place was repointed some time ago and they didnt rake out the old mortar

[royclarke]

That's about the same age as our house, though we were fortunate, the repointers hadn't got to it. It's a sad reflection on so called "professionals" in that they do work in a way that increases the problems. If only they wold lime mortar (that's assuming it was necessary in the first place) it would add to the life expectancy. There are so many places round here where they have done cement pointing, and the cement is still there, just the bricks are disappearing.

[mrgrimsdale]

Yes spot on - the mortar is too hard for the bricks and they are deteriorating fast by the looks of it.
9 finger's mortar looks OK - DON'T REPOINT!!
Part of the problem there is that the sash has come away slightly from the masonry which often happens with brickwork but not so bad with stone jambs for some reason. You get a ratchet effect where a bits of mortar or brick spall drop into the gap and wedge it slowly wider.
This is another good reason for taking it out entirely - you can put it back properly, although sometimes you can push them back up tight without first removing them, as they are already a bit loose. But it can be difficult to get at the wedges.

cheers
Jacob
PS what was it covering the gap - it looks like a bit of something was removed?

[dirtydeeds]

part of the outer cheek has been removed because it was rotten. in this particular case the horn and back of the box was in good condition

if the level of rot in the cill is worse and the horn has gone you have to replace the whole cill

note well, if you dont replace a rotted out horn two things happen, water penetrates into the house and in 5-6 years you will have a MAJOR repair because the horn is holds the weight box / frame construction together and the box starts falling apart.

to replace the whole cill you remove about 400 of the outer cheek and about 600 of the mortar and some of the box back (if that hasnt rotted away already)

the removal is necessary to install the new cill and give enough play to get the 3D jigsaw of box back, outer cheek and pulley stile back into place

ive never yet found any wedges. mortar removal is done with a 200mm bakuma pry bar used as a bolster

in my experience only bakuma pry bars can take this level of punishment

[mrgrimsdale]

Well I've always found wedges though they are not always conspicuous. There is usually at least one at one end of the cill and usually one or a folding pair at both ends of the head. This is the standard trad way of fixing a sash. No other fixings are used except for the plaster.
Re back of boxes and mid feathers - I see you have both in your example. Box backs are often left out in stone buildings as they don't serve any purpose - and ventilation is better without. They are needed in brick buildings cos of the build up of debris - bits of mortar etc but if this is really bad the back of the box tends to rot and everything fails, they just delay it a bit. Mid feathers are a textbook thing which are often omitted - again they don't serve much purpose other than stopping the weights dinging each other. But they create a problem when they become detached and can jam up the works no end.
I've always worked in oldish buildings so hard mortar is not common which makes removal of an an old window a lot easier. Lime mortar is more breathable which helps with the longevity of older joinery.
NB proper lime mortar is traditional slaked lime plus sand etc which can be bought in bags wet mixed ready for use. It's not the familiar mix of cement, sand, hydrated dry lime.

cheers
Jacob

[dirtydeeds]

jacob

i dont know where you work but here in london south of the thames and out into kent wedges are not / were not used in these areas, the oldest frame i worked on was 250 years old, the youngest about 30 years old but the majority are in the 100 to 150 years old

all are hung from the horns of the inner cheek nailed to the inner timber lintol, most frames are fixed in place with a weak type of plaster mix bulked out with wood shavings and sawdust.


box backs do serve a very important purpose, they are a structural member of the frame, boxes without backs flex and move

the parting slips are not "just a text book thing" and their purpose IS NOT to stop the weights dinging. they have a far more important job, they stop the weights getting hung up on each other

and when the parting slips have rotted out they do get hung up

scotland is the only area of the country where parting slips are ommitted from the consturction, scottish sashes have wider parting beads (13mm not 8mm) mainly because of more severe weather, so the weights are further apart in the box

scottish weights have conical tops to stop the weights getting hung up, if it was just a case of dinging they wouldnt have conical tops

the only area im aware of where there are not backs to the boxes is pimlico but here the splayed inner cheeks of the building are used as a structural part of the box

some buildings in kensigton have slatted backs but they are still a structural part of the box

all modern (box sash) frames have backs and all (to my knowledge have) parting slips

[mrgrimsdale]

dirtydeeds said:

jacob

i dont know where you work but here in london south of the thames and out into kent wedges are not / were not used in these areas, the oldest frame i worked on was 250 years old, the youngest about 30 years old but the majority are in the 100 to 150 years old

all are hung from the horns of the inner cheek nailed to the inner timber lintol, most frames are fixed in place with a weak type of plaster mix bulked out with wood shavings and sawdust.


box backs do serve a very important purpose, they are a structural member of the frame, boxes without backs flex and move

the parting slips are not "just a text book thing" and their purpose IS NOT to stop the weights dinging. they have a far more important job, they stop the weights getting hung up on each other

and when the parting slips have rotted out they do get hung up

scotland is the only area of the country where parting slips are ommitted from the consturction, scottish sashes have wider parting beads (13mm not 8mm) mainly because of more severe weather, so the weights are further apart in the box

scottish weights have conical tops to stop the weights getting hung up, if it was just a case of dinging they wouldnt have conical tops

the only area im aware of where there are not backs to the boxes is pimlico but here the splayed inner cheeks of the building are used as a structural part of the box

some buildings in kensigton have slatted backs but they are still a structural part of the box

all modern (box sash) frames have backs and all (to my knowledge have) parting slips

Interesting. I've done 100s of sashes all over the midlands and also in Ireland. Average age about 150 yrs. They were all wedged without exception. Non were "hung" with nails. Do you mean by "horns of inner cheeks" the top end of the inside lining?
Box back linings I've encountered have always been a bit flimsy - just rough sawn 1/4" scrap, which often has come loose and blocked the weight movement, and they are often omitted altogether. Without them makes a sash much easier to fit - the inner linings are left off until after fitting the frame and so are not easily joined to the box back lining if present. NB this is good tip for fitting sashes - leave off the inner linings until last, you can then scribe them to fit the masonry and make the whole thing a good fit
"Parting slip" here is called "mid-feather" and is not at all common. I've met a few when they have come detached and I've had to extract them to free the weights - which work OK or better without them. As you say - they must have rounded ends, but if the right size and vertical then they don't touch. Or if they are that close then a mid-feather creates friction and wears out - which is why they fail, but after a long time.
Parting "bead" comes in all sizes from 6 to 12 mm. praps 5/16" most common.
Most of the "correct" text book details seem to get used in better quality later windows circa 1900 but by then they were just going out of fashion altogether. Also get pocket pieces in the middle of the pulley stile with the parting bead going through. A difficult and pointless detail IMHO.
Some of the most interesting ones I did were about 1810 and in Co Mayo in a big house. they had all sorts of original, functional but unusual details - such as a reduced cill only half the width of a conventional one i.e. they left off the front edge which is most prone to rot. The front edge of the bottom sash rail projected infront of the front of the cill IYSWIM, so weathering the whole thing from top to bottom.
If I'd lived there they would have been just about renovatable, but not possible at a distance so were made back here and taken over.

cheers
Jacob

[jfc]

jacob

i dont know where you work but here in london south of the thames and out into kent wedges are not / were not used in these areas,

Yes they where . I've lost count of how many sashes i have refurbed and replaced in and around London . They all have had wedges holding them in .

I have a theory that the nails in the head where a temp measure by the fitters while they wedged the sash in place as nearly all the windows i have removed the nails have rusted through if any atall .

[mrgrimsdale]

Glad to hear it's not just me and the wedges. Was beginning to wonder if I'd been hallucinating over the last 25 years. (I was a bit but that's another story )
Perhaps dirty d hasn't seen too many wedges cos he does repairs in situ?
I've never worked much south of Derby, perhaps there is a north south divide in sash designs. It'd be south of Leicester I guess - or some other god forsaken southern 'ole ;D

cheers
Jacob

[dirtydeeds]

good job i use galvanised screws foam and clamp them in place while the foam goes off

is there any need to scribe, you generally fit architrave round the windows

the other thing is there is 2 to 3 inches play both sides of the box which would make for very wide inner cheeks

yes i call the inner and outer linings cheeks

there could be something in doing repairs insitu and not seeing wedges

[mrgrimsdale]

dirtydeeds said:

snip
is there any need to scribe, you generally fit architrave round the windows
snip

Most of mine were in stone buildings with wide reveals. So the linings would butt up to the masonry, then you'd get plaster or panelled linings or even great constructions of internal shutters. Architraves on sashes in brickwork where the sash inside lining is flush with the wall, or sometimes a bit of lining and then an architrave.
The benefit of wedges for removal is that once you have chipped away plaster and removed window boards you can often loosen the wedges by a bit of tapping and/or pull them out with pliers - at which point the whole window can crash easily to the floor without any effort on one's part except for dodging out of the way
This is usually accompanied by a mushroom cloud of 150yr accumulation of fine dust, soot, birds/rats nests, squirrels' hoards, lost hamster corpses, hibernating butterflies and wasps, spiders, dead beetles etc

cheers
Jacob

[dirtydeeds]

thick stone walls explains a lot of the differences in our techniques and approaches

id love to work on such a building because the work is so much more complicated

i love doing work nobody else will attempt







for that experience ill even use wedges