Sunday 20 July 2014

Waterproofing the Walls

Getting the waterproofing right in an earth sheltered house is an absolute must.

In Crete, with its undulating terrain, there are many villages that are built on hillsides and the traditional village houses often have a back wall cut into the earth. This being the case we were able to enlist the services of a team that specialises in waterproofing such buildings.

After a long debate and the running of various models of the design, with and without insulation, it was concluded that, for the exterior walls, omitting  the insulation enabled the high thermal mass of the exterior walls to remain at earth temperature throughout the year.

For the roof, however, 10cm of insulation was needed to counteract the intense summer heat that would penetrate through the surface layers of the earth sheltered covering and provide sufficient insulation to ensure that, in winter, any heat produced by the wood fired stoves would be retained sufficiently by the high thermal mass.

The waterproofing process for the walls had a number of stages. First any sharp edges left from the shuttering were removed,  the bolt holes for the shuttering were then plugged and smoothed over before a cement spray was used to give a thin uniform coating. Then a thin insulation layer was applied to act as cushioning before the waterproofing layer itself.

Plugging the shuttering bolt holes.

Applying the thin layer of insulation to act as cushion. Note the "sprayed wall" in foreground.

The first roll of waterproofing is positioned.

The west wall is waterproofed.

Spraying the smoothing layer onto the roof.

The slow steady process of preparing for the roof insulation and waterproofing.