Wall Built In Letterbox - Installation Guide

Equipment needed

What you need to install your letterbox will vary widely depending on the type of letterbox you have and the type of wall you have. We'll leave this part up to you to decide based on the variables mentioned in the guide below. The one main component needed is liquid nails/sikaflex. 

Creating the cavity in your wall

99% of the time, installing a letterbox in your wall is not a DIY job. It generally involves the work of a full team of tradies, brickies and landscapers. Once all that is taken care of, it really is as simple as leaving a cavity within the wall for the box to slip into. There are two ways to go about this...

Installation Channel

Available on our online store is a handy little piece of metal we call an Installation Channel. This is made from thick galvanised steel making it strong enough to have bricks built on top, and to take the weight of other materials around it. It will provide the perfect template or guide for the letterbox to be slotted into once the wall is complete. Note there are two sizes, landscape and portrait based on the size of box you order. The channel is also telescopic to match the depths of a telescopic box if needed (between 250 and 470mm).

Hand-building the cavity

The other option is to build the wall while leaving the cavity to the correct size, without any template or channel. For this you will need to find the dimensions of the product you are building-in (easily found on the "Specifications" tab on each product page), and allow some clearance 5-10mm on each side. E.g a Superior which features box dimensions of 340mm wide by 140mm high, we'd recommend a cavity size of 350mm wide by 150mm high. 

The end result will look the same as above images, but there comes greater risk that you get the cavity size wrong. If you're confident enough though, go for it!

What not to do when building your letterbox into a wall

We'll put it simply, do not build the bricks or any material on top of the box. The boxes are made from aluminium and are not built for structural use. If you were to place the letterbox within the wall as you bricked it up, the weight of the bricks on top of it would crush the box and destroy the whole thing. Always build the wall leaving the cavity, installing the letterbox within afterwards. 

This is especially relevant for gabion walls. Gabion walls feature a metal cage with rocks poured freely to fill the space. While they can look nice, they can be a perilous installation for our letterboxes. 

If for example, you poured the rocks directly onto the letterbox, the weight and/or impact would destroy the box and the faceplate would fall off. Please do not do this. You can still use our letterboxes within a gabion will, but you will need either our installation channel mentioned above to shield the box from the rocks, or some other ways of creating a solid structure for the box to sit in. You will also need a way to fix the faceplate to the wall - we'll leave this up to you. 

What next?

So you've built the wall and left the perfect-sized hole to insert your letterbox. Go ahead and slide it in through the front. For telescopic boxes, first measure the wall depth and rivet together the two telescopic parts to match the depth.

To fix the faceplate to the wall, use liquid nails or sika flex around the back of the faceplate to adhere it to the wall behind. You can use some around the outside surfaces of the box to help it adhere to the inside of the cavity too. 

The rear flange can then be placed around the back. This will frame the box in the wall and hide the rough edges of the cavity. If your box is deeper than your wall and protrudes outside the wall, the flange can go back flush against the wall. See below examples...

Letterbox and wall at equal depths, flush with rear flange. 

Letterbox protruding, rear flange flush with wall. 

Custom faceplates in walls

For custom laser cut faceplates, please make double sure that the faceplate has enough adhesive to independently support itself. When we manufacture laser cut faceplates, they are stuck to the box with heavy duty double sided tape. While this is very sturdy and near impossible to come undone, we have seen it happen when too much weight or pressure is put upon it. If the faceplate has adequate adhesive sticking it to the wall, and the box is snug and properly secured in its cavity, you shouldn't see any issues. 

Built in wall letterboxes

That about covers it! If you have any questions we are always here to help! If you're still looking for letterboxes, check out our range of built in letterboxes and see what you find.