Fitting an Iron Air brick

  • lay a bed of mortar along the base and on the edges.
  • Secure the GRID3 in the vacant hole utilizing removable wedges or card as shown below (we recommend using traditional materials such as slate to act as packing, mortared in permanently).
  • Tradesmen in Georgian, Victorian and Edwardian periods would have used traditional materials for packing and we would advise to use the same. Slate is a fairly obvious choice although wooden wedges and even flat shells and pieces of brick will also work well. It is important to pack the material between the cast iron and the brick so the air brick is firmly held. Tap the packing in, ensuring the cast iron air brick isn’t struck with the punch or the hammer otherwise it may fracture and finally remove any protruding packing so the mortar can be pointed over.
  • Point in around the edges and along the bottom, removing and discarding the packing material if it is protruding.
  • Point along the top last, being careful not to force too much mortar into the void – ensure the holes are kept clean by clearing them with a pencil or old drill.

As soon as you have finished, give the air brick a wipe over with a damp sponge and gently remove any mortar from the metal.

After a couple of days poke through the holes to ensure all the large pieces of loose mortar are away from the vent holes.

Now lightly scrape with a stiff brush across the mortar pointing to bed it in and remove any excess.
If the cast iron air bricks are painted and all the mortar was sponged off they should just need a buff up with a polishing cloth or duster.

If they are bare metal just leave them to develop a light rust – this will protect the iron air brick.
If you have installed cast iron hit and miss vents then we recommend spraying them periodically with preservative such as WD40 to ensure they remain operational – they shouldn’t be painted.

On no account should cast iron be painted with water based paints or emulsion.