Rubble

I won't bore you with yet another photo of the chimney today. Suffice to say I got up early and started my day job at 05:30, thus allowing me to finish early and spend the afternoon reducing the chimney still further. It took a while as the cement seems much stronger, and because I am in the area of the fireplace, and the ashpit where there are more intricate structures to demolish. In the end the pile of rubble grew to meet the diminishing chimney and I had to stop and barrow some of it away.

I don't know if I have mentioned this before, but we have a disused stone quarry in our garden, affectionately known as "the pit" (this is distinct from Adam's bed which is also "the pit"). This is to be the repository for all the rubble from the chimney, and the diggings out for the basement room and foundations. Hopefully we will be able to build up the floor of the quarry a little, and make it into a usable area of the garden. At the moment it simply hosts the fortnightly bonfire to get rid of prunings and weeds.

Whilst filling the barrow I got thinking about the science of dumping rubble in a hole. If the pieces are too big they will lodge against each other, and leave air gaps. From the top-side all will appear solid, but over the years, my guess is that you would experience significant subsidence as the rubble breaks up and collapses into the air gaps. For this reason I was careful to make sure that the big stuff was mixed in with smaller grade stuff. This is a good reason for doing these sorts of projects yourself. The pro's simply don't have the time or inclination to worry about these things !

I have been surprised at how little the chimney has been tied into the current building, and also how few wall ties there are binding the stone outer course to the block work inner. The inner blockwork core was not tied into the house at all. The outer stonework was butted up to some metal plates bolted to the wall, with a bar bent outwards to sit in the horizontal mortar joint every 2ft or so. Are there any experts out there who can comment on this construction ? Seems pretty weak to me. I reckon after 10 years or so the whole lot would have started to part company with the house. As for wall ties - I did not find any higher than 6ft from the ground. Again, is it normal to wall tie more lower down ?

Lastly the cavity - isn't it normal to keep the cavity clear to prevent damp ingression ? This was certainly not the case here - full up with rubble, cement, bits of platerboard, broken roof tiles. Does damp not matter in an external chimney like this ?

Guess I should go check the building regs......