"I had a bespoke size letterbox which solved all my post problems"
P. Vaughan, Croydon
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How to Install the LS12 Thames letterbox into a wall being built

4 Steps to fitting your LS12 Thames postbox into a brick wall being built

LS12 Postbox being fitted into a brick wall

Step 1

Build the wall up to the required height then build in the containing section of the mailbox, the bottom should be started on a new course of bricks and be bedded into cement.

Note: If the slate front is to be proud of the brick wall then the front of the containing box should be flush with the face of the front wall. If the slate front is being recessed into the brickwork then the containing box should be set back the distance the slate front is to be recessed + 3mm. I.e. If the slate front is to be recessed 10mm then the containing box should be set back 13mm.

Complete the wall and allow to set.


Mailbox being built in a brick wall
Recessed postbox

Mail collection container set back for a recessed slate front.

Cut a recess around the mailbox container

For recessed slate fronts cut a 18mm border around the perimeter to the depth of the front face of the containing box.

Apply glue to postbox

Step 2

On the back face of the slate front, apply a bead of glue suitable for exterior use (such as No More Nails) 10mm from the. Also apply glue to the front of the containing box.

Assemble letterbox front and postflap

Step 3

Align the slate front with the front of the containing box and push the faces together.

Ensure the slate front is square then with the help of an assistant fix the letterplate and and faces together with the 50mm bolts, washers and nylocs. The nylocs will need to be fixed from the access door of the containing box. If the containing box is deep then the back may need to be removed.

Note: DO NOT OVER TIGHTEN THE BOLTS as this may damage the slate.



Exploded view of container Exploded view of containing box.

Support mailbox

Step 4

Apply a support until the glue has set.

To seal the slate face, run a bead of clear silicon around the sides and top edges (not the bottom) between the slate and the face of the brickwork.



Exploded view of the Thames mailbox:

Exploded view of Thames mailbox

A) Pan head bolt (x4)

B) Letterplate

C) Slate front

D) Containing box front

E) Rubber seal (x2)

F) M6 Washer (x4)

G) M6 Nyloc

H) Centre sleeve

J) Nylon washer (x4)

K) Brass T Nut (x4)

L) Securing stud (x4)

M) Containing box back



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Lettasafe, Unit 4 MB Site,, Norwich Road, Norwich, , NR13 4EZ, telephone: 01493 753 288