Airbrick cover

My Heating Oil boiler now has a balanced flue, so longer needs the large Airbrick. DO NOT USE IF YOU HAVE AN OPEN FIRE OR A BOILER THAT GETS ITS AIR FROM INSIDE!  SAME APPLIES TO AIRBRICKS NEEDED FOR VENTILATION PURPOSES. So, I designed a cover based on a design of a Air Brick Flood Prevention Metal Plate Cover found here. https://floodkit.co.uk/products/airbrick-plate Used Four 10x50mm Plugs into the holes of the Airbrick, M6 Threaded coach bolts and some nylon washers (Suspect M8 bolts would break the Airbrick lattice, the M6 bolts hold it fine.) I printed a template to get the holes in the correct place. My airbrick is around 215mm square, this cover fits nicely onto the airbrick inner surround and is some 194mm square.  I used 6mm Thick - Adhesive Backed Neoprene EPDM. M6x40mm Hex Head Coach Screws were used. You can see where I put the plugs into the Airbrick. If I was critical, I’d say it needs a few more bolts since the middle bows slightly or reposition the bolts so they are more central to spread the compression. Nice to have a solution that doesn’t need holes making in a wall!