Will mud bricks wash away?
The short answer to this question is no they won’t. This short answer needs, though, to be qualified. Firstly it is assumed that the question refers to handmade puddled mud bricks, not other types, like hydraulically pressed blocks. Secondly, because The Mudbrick Circus has taken care to develop durable bricks, (Note the addition of a small amount of lime in our blocks to enhance their resistance to erosion) bricks purchased from our brick site will generally have better erosion resistance than others. The following notes and advice is only in regard to natural bricks which we manufacture. Let us examine what actually happens when a brick erodes. Just rain on mud brick walls does not generally mean erosion problems. Bricks can get wet and dry as many times as you like and will not erode. For a brick to erode, it must firstly get really wet over a long period, when the ambient temperature is low and/or the humidity is high. An example of this would be say eight hours of wind driven rain on a wall during June, July or August when outside temperatures are at their lowest and when there is no evaporation. The second factor which needs to be present, after the wall is thoroughly soaked, is the occurrence of wind driven rain. If these two factors occur for long enough, and with enough severity, your mud brick wall may show signs of erosion. The next step to remedy this sort of problem would be to apply a sealer to wall to limit wetting or perhaps shelter to limit wind. To limit wetting, we recommend Tech dry Weatherseal. This is a silicon product which will allow water vapour to move in and out of the bricks (the wall can breathe), but rain will not penetrate. To prevent erosion in the extreme case we have just described, you only need to limit one factor out of the two mentioned. You can either prevent wetting or you can limit wind speed. The most likely areas where erosion will be a problem are coastal regions where wind and rain occur together. Other places, such as the Dandenongs east of Melbourne, may have high rainfall but sheltered conditions. In these regions the very wet conditions alone, without the assistance of a stiff breeze, will not cause erosion.