Soon I will have to make about 15 replacement windows. They will be softwood frames and probably traditional casements. The Cills/sills I would like to do in hardwood. I was wondering what are the current preferred options. Iroko is durable but is pita to work. Oak is a possibility. Mahogany is a waste and ethically questionable. Any ideas please?
Window Cills/Sills
- Thread starter PAC1
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Not really much help, but i would choose iroko. Besides the dust its not that bad to work with-get use to it after a while. Expect to change your planer blades a little sooner, but then, its alot cheaper than oak !
Simon
Simon
RogerS
Established Member
PAC1":17sw1t0f said:
A good question. I posed a similar one over on the other forum but my question was one step earlier on in the process ...why hardwood?
Reading round all the texts on window repair and restoration, the general consensus seems to be that when you replace or repair a window to use similar wood. Otherwise the differential expansion/difference in moisture absorption etc means that there is an inherent weakness just waiting to be exploited by nature.
Extrapolating this then begs the question - why do we all go and stick hardwood cills on to softwood frames?
SNight
Established Member
My first choice would be iroko, if you don't fancy that, then another type of timber would be sapele.
I would say it is always better to use a hardwood cill if possible, because that is where most of the moisture ends up from a window, either from above, ie: Rain water or condensation running down the window on to the cill. Or from below, if sat on a stone cill, or in the case of a door frame, close to the ground.
A hardwood such as Iroko is a lot more durable to these type of conditions, than a softwood, so it does make sense to use a hardwood cill.
I would say it is always better to use a hardwood cill if possible, because that is where most of the moisture ends up from a window, either from above, ie: Rain water or condensation running down the window on to the cill. Or from below, if sat on a stone cill, or in the case of a door frame, close to the ground.
A hardwood such as Iroko is a lot more durable to these type of conditions, than a softwood, so it does make sense to use a hardwood cill.
joiner_sim
Established Member
I would say the standard choice of hardwood for a window cill is sapele. With ideally a 5 or 9 degree bevel on to help drain the rain water.
RogerS
Established Member
SNight":3cn7djxz said:
But that was where the rot set in...literally and metaphorically. Pack it away from the masonry so that the cill doesn't sit in a pool of water.
Thanks for the suggestions. I think I will try Sapele. Looking at its properties they are not to dissimilar to Iroko but without the cancer risks and not so hard on the planer blades.
As for damp problems, I always sit windows on dpc material stuck on with plenty of mastic.
In my experience it is not just stone sills that cause a problem you should protect woodwork from any stonework. I advised on one dispute where the windows were sat on dpc but the jambs were not protected. The frames rotted from the sides in less than 5 years. The sills were fine!
As for damp problems, I always sit windows on dpc material stuck on with plenty of mastic.
In my experience it is not just stone sills that cause a problem you should protect woodwork from any stonework. I advised on one dispute where the windows were sat on dpc but the jambs were not protected. The frames rotted from the sides in less than 5 years. The sills were fine!
