How to dig footer for front fence?

[Eli_S]

G'day,

My wife and i are planning to put up a front fence, out of brick which will later have a gate for our driveway and pedestrian gate, my brother inlaw is a bricklayer so he'll do the actual brick work but I'll need to do the footer. Just looking for confirmation on how to do it. I know the footer will need to be 600mm deep, and i think it's going to need to be 380mm wide (twice as wide as the besser blocks). After that is done I'll need to put in trench mesh put in concrete and rebar that will go up the pillars of the wall. What type of concrete will i need and how much mesh. Also i have three pipes going through the footing area, all strom drains. Do i need to do anything specific around them? Thanks

[Jewelleryrescue]

Hi @Eli_S 

A front fence is typically not very high waist level so thats 3 bessers  (8 Brick) high 600mm  so if you do your footing 400Deep  x 300 width  with  reo that will be plenty strong.  The gate post could be 600 deep.   Trench  mesh  comes in varing sizes depending where you buy it bunings has 1800mm x 200 x8mm  where as steel suppliers  can  sell you 6 meter lengths. Shorter  lenghts need more over lapping and tieing  so it depends on the lenght of your wall as to how much ,  For example  a 10 meter wall would use 2 lenghts of 6 meters over lapped bunnings mesh 1800mm x 6 lenghts. more work.  I have never heard of rebar going up inside a brick wall pillars if  bricks are being used they dont need reo for strenght.?

I would put  your  pipes in sand to support them and run the  bricks  across them.  Sand also makes it easier to dig the pipe out if repairs required.

Umm run you pipes besides the brick work not parallel underneath.

Use  standard  general purpose cement and  brickies sand  1 cement 2 sand 3  stones.  Your brickie  may offer variances on that mix it is not critcal as it is a mass concrete footing not skyscraper foundations.

Do use plastic in the trench this will give smooth rounded and there fore stronger concrete footings.

Method

Dig your footings out 400x 300   lay your pipes adjacent to brick footing. Go 600 deep on gate post footings. 

Sand your pipes  cover trench in  plastic . I nsert mesh and tie it together raise mesh to middle concrete level with old bricks etc

I use strips of cut up  corflute to form neat parallel top form works Corflue  plastic so you need 1 meter  stake supports.  Your  form work creats the  ltop level for your brick work so get this nice and  level and straight.  Or use old pailings the straight ones as  form work.  

Pour  your cement a reasonably  sloppy mix to  fill the  form  work.  Trowel the top smooth  sign your name in cement  wait aweek and your ready for bricks.  hope some of this helps.

[MitchellMc]

Welcome to the Bunnings Workshop community @Eli_S. It's marvellous to have you join us, and many thanks for your question about creating a block wall.

From my experience, that sounds like an incredibly large foundation for a block wall; it even sounds overkill for a retaining wall. Have a look at the video from Abri Masonry on block wall installation. Typically, the wall is constructed on a compacted base, and only a small layer of concrete is used to bed the bottom layer of blocks in place. Obviously, if you or your brother-in-law want to create a more substantial foundation, that's up to you.

Standard concrete would be suitable, but for that size foundation and depending on the length, you might like to look towards having a cement truck pump the foundation as that would be an incredible amount of pre-mixed bags. Here's a handy calculator to determine exactly how much you'd need. 

For the mesh, I think you'll find that a couple of these trench meshes side-by-side and slightly overlapping would be adequate.

For the pipes, you'd likely need to disconnect them, form up some channels through the foundation and then re-install them once the foundation is cured.

Please let me know if you have any questions.

Mitchell