Moving my farmhouse upgrade to its own thread. Just to put in context we have an old stone farmhouse the date stone reads 1721 but thats when the property was extended at the rear with the addition of a weaving shed and at the side with a new doorway and chimney. The experts reckon it was actually built around 1650. We are having real issues with our conservation officer. Doing anything to the house even simple things like replacing rain spoutings we are still waiting approval after 3 years. In the end we have done the work anyway on the advice of English Heritage as a like for like repair. We have started to create a warmer house by installing 600mm on insulation in the loft which has made a big difference. Walls are all 2 foot thick solid stone but biggest heat loss is through the single glaze windows. We used to be on oil for central heating and an Aga cooker which has been replaced by a wood burning Esse cooker and a Dunsley Yorkshire central heating boiler.

Posted by John in another thread...

I am looking to put triple glaze units direct into stone mullion frames is there any sealant you would recommend for this . I was going to use standard insulation foam to allow the window to expand.

......................

Sorry John. No experience of doing that onto stone. The only (and it's a stretch) similar situation was single glazing into old oak mullions which was bedded-in on transluscent acrylic sealant and then puttied. 3g straight into stone mullions? The face onto the rebate isn't a problem with the bedding bead of sealant (and the unit sitting on packers to even it up), whichever way it's glazed (internally or externally), it's making it look "right" on what would otherwise be the glazing-bead side.

What I could have made clear in my rant to Tom (sorry mate) was that the way I do it avoids the interaction predicted between the sealant and the hot-melt more by accident than design, because that's the way I've always done it in ignorance of the science that says it's critical to avoid it. Back to the old "He didn't know it was impossible" scenario. The method I use (and which others who've now taken to using the method have adopted) had more to do with getting away with using as little as possible rather than avoiding contact with the unit's edges - although my method still advocates the use of "copious amounts", the squeezed excess guaranteeing a good waterproofing seal, which is the whole point.

Having said all that, in the early days I DID apply the sealant all round the unit and only stopped because I wondered if there was a less expensive way of achieving the same end than just throwing gallons of sealant at it, and those windows are amongst the ones still going strong.

Is there absolutely no way of getting even a minimal frame of sorts around those units, John? I'm always reluctant to trust the tape edges that units usually come with because I've seen systems fail by moisture weakening the tape edges, enough to allow water to find its way around and under the tape to the inside of the unit, but that was on a conservatory roof and it took ages to realise what was happening! Since when I always stipulate "no tape" on every unit I order.

So I'm out of ideas based on first- or even second-hand experience.

...........

Posted by fostertom...

"renewablejohn, are your stone mullions glaze-in or glaze-out? In other words, did the original putty splay face inward or outward? this is a situation I'll prob be facing myself shortly - I'm hoping they're glaze-in, but fear they're glaze-out, which is def more tricky.

One time, in 1G days, I fitted a thin 'frame' of aluminium odd-leg angle, made up welded at the corners, tight into the rebate of somewhat wavy/decayed Bath stone mullions, to provide a flat (and slightly widened - visibly, but didn't seem to matter) rebate 'floor' to direct-glaze fixed glass to, and also to tap and thread into for hinges for some timber opening lights incl draught strip against the flat Al face. This was glaze-out. Worked v well."

...............

Joiner...

On the stone mullion glazing... Of course, it's usual in this situation for the glazing to be in edging of some kind, often lead cames. Which makes me wonder about retaining that "traditional" method by edging the 3g units with lead (flashing) and sealing along the edge of that with sealant prior to puttying because, drying clear, it'll be virtually invisible. In fact that's probably the way I'd go if I was doing the job.

...................

Tom...

You'd actually form a lead U-channel (like a came) to hold the 2G/3G unit, and mastic the lead to the surround?

...................

Joiner...

I can't think of any better way, it's just an "enlarged" version of the s/g traditional method and could, with care, be dressed around the unit.

.....................

John...

Great idea with the lead flashing. My windows are only 12 inches wide and the plonker of a conservation officer insists that we replace softwood with oak frames with all bars being the width of the opening windows so 2 inches lost on either side so now only 8 inches of glass. I have one original leaded window lime mortared into a stone mullion so the precedent is set. Unfortunately I have 82 windows to replace 22 in just one room so oak frames are totally out of it. Getting back to the lead flashing would that create a heat bridge around the edge of the glazing unit or am I getting paranoid considering the amount of heat were already losing using single glaze.

.....................

Joiner...

I think the fact that you're going to be improving the performance of what is, after all, the 'historic fabric', justifies a lighter touch on the self-flagellation.

......................

Tom...

A lead channel wrapped (dry?) around the edge of a 2G/3G unit? That channel (bottom one anyway) will fill with water, which doesn't matter with a came and 1G, but surely isn't good for the edge of a 2G/3G unit?

......................

Joiner...

Tom, seal the edges with the clear acrylic by running a bead of sealant around the outside of the unit then applying the prepared lead came profile. Dress it to a good snug fit and leave it flat overnight weighted down with a board pressing onto wood strips cut to the length of the sides to put pressure on the came edges, preferably top- and under-side. When cured, trim and run a bead of sealant along the edges of the came to even up the profile. Where the ends of the came meet (at the top of the unit, preferably though not necessarily at a corner) would likewise be sealed.

We're really only concerned with protecting the edge of the unit, and the sealant would do that, the lead came effectively nothing more than an element in that edge protection.
.........................
(Phew!)

Okay so we have a 3G unit with silicon around and then lead but how do you then fix into the stone. Simple expanding foam but would that be able to cope with different expansion rates of stone and glass. The south facing stone does get quite warm in the summer. Still not sure on heat bridging of lead or would it be better having a split lead bead with an insulation gap.

Posted By: fostertomSo, are the mullions glaze-in or glaze-out?

I dont think there either. Basically the stone mullions are a diamond shape with a 2 in flat where the point of the diamond would be. Windows slide in from either direction. Present wooden windows have putty on outside of frames holding glass in.

John, you could putty the units into the lead. Using the putty-in-a-tube, you can get a narrow bead around the unit's front edge.

http://www.topclasscarpentry.com/product/59022/

It does what it says on the tin.

B&Q also sell the stuff and that dries like conventional putty.

I suspect that (especially given the area you're in) the CO might insist on a traditional "scotch mastic", or burnt-sand mastic (half way down the page)... http://www.womersleys.co.uk/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww.womersleys.co.uk%2facatalog%2f&WD=burnt%20mastic%20sand&SHOP=%20&PN=Building_Products_4_4.html%23a23#a23

I'm not a fan because it goes rock-hard over time and hair-line cracks appear between it and whichever material is the most prone to expansion and contraction it's been applied to.

Whenever it has been insisted upon I've used a bead of sealant to seal edges and then finished off with the stuff.

Would it be that great with 3g? Stiffer than single glazed and more thermally stable?

Think you need one of the numbers men to play around with that, but instinctively I'd be happy to just go with it.

But then I didn't know where the bloody sun rose and set!

At least the CO is allowing 3g, which totally gobsmacked me.

Posted By: djh

Posted By: renewablejohnSorry rubber would not be allowed as it was not a material in use at the time the building was erected.

But float glass was?http://1.2.3.12/bmi/www.greenbuildingforum.co.uk/forum114/extensions/Vanillacons/smilies/standard/shocked.gif" alt="" title="" >

I'm surprised they let you put any glass at all in the windows if they're so keen on authenticity!

Dont give them bright ideas. I know the building did not have glass to start with as the stone lintel and cill has a diamond shape cut into it where the steel bar used to fit.

Posted By: renewablejohnNot the best of photo's

true - looks like a graphic off horror story bk cover

Amazed the CO didn't insist you keep them all. They would have around here and then suggest secondary glazing!

Posted By: renewablejohnbut when your threatened with enforcement for actions taken by previous owners non compliance and mismanagement by a previous CO it does come as a bit of a shock.

What..? They want to slap you for issues which were absolutely nothing to do with you..? Seriously..?

I'd like to see that one stand up

Is that not akin to subsequent owners of Fred West's house being arrested for burying people under the patio..?

Posted By: JanitorIs that not akin to subsequent owners of Fred West's house being arrested for burying people under the patio..?http://1.2.3.12/bmi/www.greenbuildingforum.co.uk/forum114/extensions/Vanillacons/smilies/standard/confused.gif" alt="" title="" >

No its more a case of did the house you just buy have planning permission for the extension. Normally it is covered by solicitors questions at time of purchase. Unfortunately there is no similar questions for Listed Builders although liability does pass to the new owner at time of sale. If I new the consequences then we would not have completed without an insurance indemnity for the works to be undertaken.

There is no immunity from enforcement over time with listed buildings, i.e. no limit to the time period after which enforcement can be pursued.
It means you can't use the excuse "it was like this when we bought it... honest!"
Unfortunately it does mean the well intentioned can be left clearing up someone else botch job after a routine or genuine enquiry at the Council office for advice.

Well informed co-operation is the best route. (i.e. do your own research etc. and well-inform yourself!)

And in all dealings with COs, get everything in writing, even if it means taking detailed contemporaneous notes and sending a follow-up letter containing a transcript of all conversations, insisting on an acknowledgement. That's the lesson from long experience talking!

It isn't always that COs will deny something they've said, but can be because they tend to move around a lot and many of them don't keep any detailed records. There are exceptions, but in my experience they're in the singular.

And don't expect consistency within the same office or local authority if you're still in a county with District Councils. In fact if Shropshire is anything to go by, even if you're in a unitary authority!