Crittall window question

No sign of that when some of mine had to come out.

Thermal break? Airflow restriction?

the wood might stop some internal air circulation - a bit doubtful. The only thing I can think of is that sealants weren't so good in the

Thanks, that's interesting to know

What about the glass? Will you be able to reduce heat loss by using a type of double glazing?

Having refitted the first one today the answer became obvious. The wooden frame rebate is 3-4mm wider than the Crittall window so without the wooden in-fill it would be harder to get the sealant to, err, seal.

Even if you could, heat loss through the steel frame is substantial. Secondary glazing solves this. Crittalls really are dire for heat loss.

NT

Wonder if an attempt to help prevent the glass cracking in hot weather?

Modern flexible putty likely does the same thing.

So are the aluminium patio doors that I have. In winter condensation pours down the inside of the metal, and in summer (south facing) I have to keep the curtains shut because of the heat coming through frame and glass.

Burglars don't like crittall windows though :-)

There was a Grand Design program filming an old industrial building being renovated near Bath somewhere. Planners said 'Crittall' windows had to stay but they got some double glazing units with a vacuum between the panes and only a very small gap so they fitted the reveal intended for single glazing. Not cheap.

I'm not familiar with that being done with Crittalls. But sealed dg units AIUI do need soft bedding of some sort, soft tape or PVC provide that, steel frames don't. So I'd expect increased failure rate.

How does vacuum dg work? A hard glass seal would break due to differential expansion between the panes, a softer seal would leak.

NT

I recall in the early days of double glazing long before UPVC that you coul d get DG units with a larger outer pane designed presumably to fit frames d esigned for single panes. I came across an example many years later in the back of a storeroom, I don?t think they lasted long before frames w ere specifically made to take DG units.

Richard