We live in a home that it part stone (rubble filled stone walls) dating back to early 1900’s and a later extension of block done i the 90’s. It is all pebble dashed with sand and cement. We are thinking of linking the house to our stone barn( again it has been pebble dashed!!) and putting a downstairs living area and upstairs bedroom and en-suite size circa 20 x 20 feet and high enough to have 2 floors. The problem is we have a limited budget. It would need a new floor including DPC and insulation put in and a new roof all of which seems straight forward once the walls etc have been inspected to identify if they are structurally sound and then some re-pointing work etc done. As we would like to ensure it has good insulation properties it has been suggested to me that when putting the floor in we should ‘TANK’ or DPC the walls by folding up the walls a DPC membrane and then dry lining by building a wooden frame to house the DPC and insulation etc and also be used as a framework to support the floor for the upper bedroom. I can understand how this would potentially damp proof the building especially as three quarters is already plastered on the outside. I guess there are 2 questions I have 1) if we take the dry lining route will this work and if done right will it remain structural sound and stand the test of time? 2) Is there a better way to do this? should we chip the pebble dash off and is there way to then create a very warm and insulated property? I guess it comes down to the funds as well but I want to know the options to consider, with potential pitfalls.. Any advice will be welcome

  • Peter Eade

    It sounds as though you have an interesting project planned. There are two ways you can deal with the solid walls of the barn, either do as you have described with a structural internal stud walls, it has to be structural as it will be supporting the first floor joists. As an alternative you could build up an inner skin of 100mm insulation blocks with the first floor joists built in as the walls are built. You will require wall ties to connect the new wall with the existing external walls. You can use cavity batt insulation with the block walls and the timber walls could insulated the same way that timber frame house walls are insulated. Which ever way you do the job you will need an inner foundation of concrete to support the new inner walls. You should discuss your ideas with the planners as they may need to approve what you are proposing. All of the alteration work will need Building Regulation approval particularly as there are load bearing walls and drain works to be carried out. There will also be a requirement to provide means of escape windows etc, etc…

  • Thomas Chambers

    Thanks Peter, you answer is useful. I am going to get get an architect or structural surveyor to look at the barn and confirm it is all viable from the structural point of view. I was a bit worried about the DPC up the walls and the dry lining as a number of forums I have looked at go on about this is bad and you should let the walls breath etc and that condensation can form behind the plastic lining and cause damage to the stone. I can understand this if it is formed bricks that have been used but the stones the barn is build of are very hard and have come out of the ground after many decades if not centuries so I find it hard to understand why stones that have been buried in damp fields would suddenly after 10-20 years start to deteriorate. I had not thought about the inner foundation as I was planning on putting a concrete sub floor in about 5 inches deep to the add the insulation and then another 4-5 inch screed to finish with the DPC in the relevant place. Any further suggestions you have would be appreciated.

  • Post a comment
    You must be logged in to comment. Log in