Lowering suspended ground floor to gain headroom

Hi Serena86153 What an interesting question and not an uncommon issue for a home of that age. Let me see if I can help ease your mind and give some guidance. First off I am unsure how pumice would help, it is a lightweight and porous material that is rarely used in any construction so unsure that I would pursue that option. Increasing the headroom will be a fairly straightforward job, you just need to be aware of a couple of things. Underpinning may not be a realistic solution as houses of that age generally have dry brick foundations where trying to put a solid concrete pin underneath may be challenging. First thing to do would be to put an exploratory hole through the floor against an external wall to find out the depth of the wall and the foundation make up (could well be dry brick corbelled out to create a broader foot for the foundation). Depending on the depth of the foundation you will be able to remove the timber joists, dig down to the bottom of the foundation and if deep enough use this as the base for a concrete slab that will act as the base for your new floor. If not deep enough you may be able to dig down a little further but please seek professional advice before doing so. The slab will need to be a minimum of 150mm thick and you will also need to introduce a DPM (the DPM damp proof membrane is crucial). This is not a complex or difficult job but helps if you employ a builder with some knowledge of historic buildings. Please give me a call if you would like to discuss in more detail.# Best of luck with your project.# Clinton Speight IPS Construction Ltd

dig the floor down to the required depth.as long as its not lower than the bottom of your foundation instead of concrete,put a wooden floor in with 100mm insulation in between joist boards on top,easy

You’ll want a structural survey before you undertake this type of work. There are plenty of routes you could take, but many would cause damp issues.

This is a fairly common problem in older properties, and removing a suspended floor can often help because there is room to lower the floor, but please, please don't put in a concrete floor. because of the age of the house there will be no damp course and so any moisture under the house was able to dissipate into the atmosphere of the space below the floor. Moisture cannot get into concrete and will therefore make a bee-line to the walls and will very quickly cause damp patches at the base of the walls and rising to about 70mm. The solution is a limecrete floor, where a floor is laid using a lime mix which is breathable, on top of a porous sub-base. Where the footings may be little fleet the foot of the walls can be banked up, to avoid any underpinning, which will, in itself cause an alteration to the moisture content of the brickwork thus accelerating degradation of the bricks Richard C L Pillinger