Pre-contract Check

[jonnydarcy]

Any thoughts from anyone re my previous post?

Cheers

 

[Deleted member 174758]

A couple. Personally I'd tend to use mastic on the frames and putty on the glazing for a sash window - they're more traditional, albeit slower to do. Absolute must on listeds and in conservation areas

I agree that a 4/12/4 DG unit in a 40mm sash doesn't leave a lot of timber to play with. I'd suggest an ultra thin unit which can be obtained down to as thin as 10mm (if you are prepared to accept 2 layers of 3mm glass or 12mm if not). These are argon-filled and are specifically designed for sash refurbs in refurbs of listed buildings, in conservation areas. One name to look for is Slimlite. Downside, of course, is cost

Big plus of going to ultra thins is that they allow the use of conventional glazing bars - so the finished window looks right - not like some cheap PVCu DG windows with a single large pane and stuck on bars. It all depends on whether or not the aesthetics of the cheaper work offends you

As to waxed cotton over nylon the answer is in the wear - nylon stretches and abrades over time, waxed cotton doesn't. As a product it has sttod the test of time

The real question is one of how traditional you want your windows to look? If authenticity is your aim, or the building is listed or you live in a conservation area then ultra thins with individual DG units is the only way to go - otherwise if seeing the back of stuck-on beads is OK then that's OK (me, I think they look cheap and tacky). If nothing else you could always go for secondary glazing inside the windows

 

[jonnydarcy]

Hi.
thanks for the reply JobAndKnock, much appreciated. The deeper one digs, the more confusion there is!

You state:

"...Big plus of going to ultra thins is that they allow the use of conventional glazing bars..."

Not sure I understand why using larger 18mm or 20mm panes would prevent the use of glazing bars?

We do indeed live in a conservation area (Stoke Newington) although looking at the building regs I can't see any reference to single DG units being compulsory. In fact almost the opposite, they want us to match the original style. Obviously with fake glazing bars you're effectively maintaining the style but only in appearance.

Looking at the single pane with stuck on glazing bars yesterday I must say that I thought they looked good. Better than 2 panes plus genuine glazing bar? Probably not but it wasn't very far off at all.

Re putty or timber beading: I was under the impression that putty (oil based ones) can lead to premature unit failure via the sealant on double glazing. Is this nonsense?

I do want to retain the traditional look but that needs to be balanced with cost and practicalities really.

Thanks

 

[Deleted member 174758]

You state:

"...Big plus of going to ultra thins is that they allow the use of conventional glazing bars..."

Not sure I understand why using larger 18mm or 20mm panes would prevent the use of glazing bars?

It would help considerably if you used the term "DG units", they are not panes. An 18mm DG unit leaves you 22mm from a 40mm thick sash. Take a look at a Georgian or Victoran sashes and you should be able to see that the lamb's tongue moulding is more than 11mm in many cases (often 1/2 to 5/8in deep). You might be able to get a router cutter or standard spindle knife to fit, but in all probability the moulding will have a squashed appearance.

We do indeed live in a conservation area (Stoke Newington) although looking at the building regs I can't see any reference to single DG units being compulsory. In fact almost the opposite, they want us to match the original style. Obviously with fake glazing bars you're effectively maintaining the style but only in appearance.

The regs are only part of the issue. Round here any change of the type you are proposing would require conformation from the Conservation Officer, but every council does things differently. It might be worth giving your local council a bell to see what they regard as acceptable before proceeding further

Re putty or timber beading: I was under the impression that putty (oil based ones) can lead to premature unit failure via the sealant on double glazing. Is this nonsense?)

My mistake. I had assumed that you were referring to SG. For DG a glazing sealant would be a better solution around the glass, but either way I'd ask the DG supplier for their take on this

I do want to retain the traditional look but that needs to be balanced with cost and practicalities really.

What would you like me to say? If you want it to look right, then stuck-on glazing bars won't ever look right. That's me showing my age - being old school, so to speak. Perhaps worth considering the effect (if any) on resale value of the house, too, because cheap-looking DG conversions don't enhance values

 

[jonnydarcy]

Mea culpa, DG units it is.

Thanks for all the advice J&K, it's appreciated. Will follow up with the council.