By shedfish , May 5, in House prices and the economy. AFAIK, red ash is waste from mining activity that was used several decades back in the foundations of some houses. Unfortunately, it was found to draw moisture into the brickwork, and quite a number of houses around here were affected, but there are others as well. I had a red ash survey done on a house I wanted to buy some years ago, and it would probably have put me off buying if the test had been positive. My limited understanding is that is red ash can cause foundations to expand, presumably buckling the floor and walls.
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Red Ash was a filling used under the concrete flooring typically between and After the war building materials were hard to come by, therefore various fillers were used and a concrete slab was formed on top of the fillers. Red ash and blast furnace slag were common filler materials particularly in areas like stoke-on-Trent where they were readily available. To sell a house with red ash, there are a number of things you need to consider:. Unfortunately, red ash contains sulphate which reacts with water under the concrete.
Red Ash – Whats The Problem?
Red Ash is a common problem in the Staffordshire region. During the post-war period, there was a real shortage of building materials hence also the proliferation of various types of system built housing and thus the government promoted the use of substitute materials. In the case of flooring it became common to use fill materials below a concrete floor. It is the sulphate content of these materials that caused the structural problems in properties where it has been used. If moisture penetrates through the concrete floor to the red ash below, then the sulphate reacts and begins to migrate into the concrete. The concrete then expands causing the floors to crown or heave. This, in severe cases, can even cause damage to the external and internal walls, by lifting and pushing them out. In what properties is red ash present?
Firstly, red ash is an issue which will be found under your floors. Even if you do not plan to sell your property with red ash, it is important to resolve the matter before further structural damage is caused. Well it is possible that your floors have ash without any telltale signs, however, those less fortunate will display signs of the floor bulging and becoming uneven. This is due to moisture reacting with the sulphates present in the red ash and causing it to expand. Often a white residue is also visible between floor tiles. Fear not, there is a cure and ash will not be present in suspended timber floors or those above the ground floor. Be sure to instruct a floor survey to be carried out before going any further. The removal of red ash is no easy task and it could result in your property becoming temporarily inhabitable. The process will require whatever flooring you have to be removed, then you will need to break the concrete sub floor, this will allow access to the contaminated ground below where the ash is contained. All of the contained ground will need removing, this can become a very physical task.