External Walls

Here we are after a slight delay, back on site. The external walls are now up to chamber, pictures here show the 190mm external walls being constructed from a new aircrete block with a thermal conductivity of 0.07W/mK and have a bed tolerance of just ±1mm which allows, as you can see, Clan Thinset mortar to be used to create a mortar joint of just 2mm.

When using Clan Thinset mortar the blocks are bonded together to produce a homogeneous aircrete wall, you can see a red mesh on one of the joints. This is Clanmesh which is a glass fibre fabric which has been specially designed and tested for use in Thinjoint mortar. Clanmesh distributes any stresses which may build up in the wall.

 

This method of construction produces a virtually airtight wall which will not require a membrane to achieve the 0.6 SCH air (changes per hour) required by the Passiv Haus Institute.

The party wall on this pair of semis is being constructed from a dense concrete block wall laid with Thinjoint mortar. This is not normally possible because the tolerance on the bed faces is not good enough to achieve the 2mm joint. However, when the blocks are laid on their side the bed face becomes the parallel side formed from the mould side when the blocks are manufactured. This method of build overcomes the problem of creating an airtight party wall, a thermally efficient party wall and achieving a sound test of of 60Db.