It is late October and it is madness to be considering lime rendering at this time of year.   Normally you would get your exterior lime work out of the way by the end of September.   The trouble is the lime will take a month to dry in cold weather and will be damaged by any frost before it is dry.  I’m gambling against a frost in November else I might have to do it all again next year.

The render will be applied onto woodwool boards which are fixed onto roofing battens screwed to the oak frame.

Both oak and lime require stainless screws.   The tannins in oak corrode normal screws and electroplating doesn’t like lime.  The holes need to be pre-drilled and a steel screw driven in and then removed to reduce the chance of the stainless screw breaking as it goes in.  There is no chance of removing the stainless screw from oak.

The bricks immediately above the oak frame were not supported and had come loose so needed to be removed and replaced again.   I have fitted a slate undercloak between the bricks and the frame.

Hessian is my plan to reduce the chance of frost damage.  It should prevent dew forming on the surface of the lime and freezing, and will hopefully insulate a little to retain heat from the wall.  It is supported on eye bolts drilled into the brickwork with a rope threaded through.   I’m hoping to come up with a plan which will allow the rope to be withdrawn from ground level after the scaffolding has come down.

More than half of the first coat went on in a day.  My current recipe for render is a bucket of rendering sharp sand, a bucket of soft sand, and a bucket of lime (NHL 3.5 to help avoid frost damage).  1:2 lime to sand is quite a strong mix, but tests with less lime proved crumbly.  The surface will be roughed and scratched when it becomes firmer tomorrow.   I had planned to whitewash the infill to match the front of the house, but the earthy colour of render looks nice.  I might try adding some pigment to the limewash.

Late October turned out to be warm and the render is drying well.   It is still drying slower than it did in the summer but that is handy as it allows me to use lime late in the afternoon and finish it the next day.  It should be possible to apply the final coat around 5 days after the scratch coat (which has been scratched).   I brushed the remaining smooth bits after the photo to help the next coat stick.

The final coat of render seems to be taking about twice the time of the first coat.   I troweled on the lime trying to make it smooth and level, then after a few hours used a polyurethane float to flatten it, filling in low spots with more lime.   Next day I went over it with the polyurethane float again, then lightly wiped it with a damp sponge to fill in the imperfections.  This left a flat sandy finish which I will claim is traditional.

The finished render is recessed about 5mm behind the frame which will make it easier to lime wash.

It’s about time the scaffolding came down.  The lime work is finished.  I used a mix of brick and tile to infill between the new and old frames and have fitted some steel to hold them together.

The new timber frame started going in on Saturday (the original was rotten).  My cousin John made it from air dried English oak.   It was nerve wracking removing the old frame – the inside of the house is full of acro props, the chimney extended to support a purlin, and various braces added to support the brickwork.  In the end it turned out the original frame had stopped being structural a long time ago.

The original wall plates are better than they look.  The ends were damaged by waterproof paint but the rest was able to dry into the bedroom wall so hasn’t been too badly damaged by beetles.  The wall plates stuck out from the wall to allow material to accommodate a fish tail joint in the tie beam.   Some lead hats were fitted before the frame was pegged together.

The current roofline is shallower than the original, and the oak timber ends behind the facia board before it meets the chimney and does nothing useful structurally.   We kept that feature because I wanted to indicate the original roof line, but annoyingly the new wood is curved and probably could have been extended all the way to the chimney.  I might stud and resin fix some new oak in place to complete the rafter.   The tie beam is extended past the wall plate (it was originally cut diagonally) so it can support the facade.

The studding is taking a long time because all the wood is a funny shape and each joint has compound angles.   The pattern of stud work matches the original apart from some slight modifications to avoid gaps of more 600mm between studs which is the width of the woodwool board infill.

The frame is starting to look nearly finished with most of the second floor studding in place.  I’ve still to finish off the barge board on the front of the roof which is tapered.  I tapered the wrong face and need to buy another bit of wood but the frame took a week and it is Saturday again today.  I’ll get on with the infill.

The front gable has an 8 inch overhang.  Originally the roofing battens were exposed but now the roof has been felted. I wanted to add some sort of cover under the felt and hit upon the idea of ply secured by strips of wood about the same size as the original battens.

I think it turned out quite nicely.

The plan was originally to sort out the timber frame in the other gable before completing the paint.  The new plan is to finish the paint, install the remaining leading, repair the paint, then ruin it all with dust when the timber frame goes in.

The leading was out of schedule partly because I didn’t notice a tiny crack in the original leading until I was just about ready to start painting.  It’s on now and just needs rendering in place and the paint touching up.