Up periscopes!

Building Regulations require a free airflow below suspended ground floors of at least 1500mm2 per metre run of wall. We are positioning ventilators down two opposite sides of the building so as to create a cross flow ventilation action. The NHBC recommend that underfloor ventilators are spaced at a maximum of 2m centres, with ventilators also positioned not more than 450mm from the ends of the wall. We can't space our ventilators evenly because of the position of the beams but we will meet the NHBC recommendation. We require 17 ventilators in total - 9 on the north elevation and 8 on the south.

We are using Manthorpe Telescopic Underfloor Void Ventilators with grey airbricks to provide the required clear airflow passage to the void underneath the block and beam floor. The plinth walls have 400mm wide cavities which means that we are having to use two extension sleeves with each ventilator. The ventilator parts are made of plastic. They don't clip/snap together and annoyingly keep falling apart so I've taped them with Duck Tape to hold them together whilst we position them. We will need to remove the tape holding the airbrick in place when we come to set them in mortar so that we uncover the mortar key around the edge of the airbrick.

#strawbalehouse #Woodlands #plinthwall #ventilators #blockandbeam #airbricks