A freezing draft and a hidden window

We are still finding out new things about the Old Brewhouse, most recently from a blast of freezing air that suddenly started coming out with unusual ferocity from the gaps round a fireplace cupboard door. Inside the cupboard, bits of plaster had fallen and a gap above the inside of the door had got bigger.

I anxiously thought – wind damage: what’s blown loose? But closer inspection showed that the wind was blowing down a narrow gap between the structure of the big brick fireplace, with its bread oven and chimney, and the clay daub wall of the house.

Chimneys were usually added to 16th century buildings in the 17th or 18th centuries and this one had had to be rebuilt 40 years ago when it was on the point of collapse. The air gap between the chimney and the old wall runs all the way up to the loft.

Inspection later revealed solid evidence that the fireplace is indeed a much later addition. Hidden up the gap I could just see in a beam the tell-tale diamonds of the empty upper sockets of a mullion window. It’s where the fireplace is, so must have been blocked up long ago to build it.

My theory is that last weekend the strong winds must have been coming from just the direction needed to get in through some loose soffits – I’d better check them all – and then through the loft and down the gap into the cupboard. If it had been an exterior hole we’d have seen damp patches in the daub. However, I resisted the temptation to climb up into the loft to check on a freezing windy night.

So the Brewhouse had at least one more mullion window, making three filled-in windows we’ve found so far, one with the mullions still present. That’s on top of the six still in use.

I blocked the wind blast, by the way, with a strip of plywood, using spare hemp insulation to plug the irregular gap around it. The temperature in the room went up.