shed base

[coco]

Hi All

I am building foundations out of bricks for a 10'x10' garden shed over an existing patio. I want the shed to sit one bricks height above the patio to allow for ventilation. Th patio is not quite level with about a 2" varience over the 10' of the shed's width. I have started laying the bricks on their sides, 2 bricks width in 6 lines, and moving to laying them flat as they go up the slope, leveling with a dry sand/cement mix.

Does anyone have any advice on doing this. How level is level? Will the dry mix I am using be secure enough on top of the existing patio?

Any help will be greatly appreciated.

All the best Colin

[Stuart Noble]

Better to use a wet (but not sloppy) mix. Have a look at

things up. You could use a length of timber instead but getting something 10 foot long and straight might not be that easy.

[Andy Hall]

50mm variation in 3m is too much for a shed base so you are right to level the base. I would aim for no more than 5mm over this distance and preferably less. Also, try to avoid making up too much of the difference using mortar, but using bricks is reasonable.

For the last couple of mm. you can always use shims under bearers to get exact adjustment.

I wouldn't use a dry mix on top of an existing hard surface. Assuming that it's sound, then conventional mortar would be more appropriate.

[coco]

I will start using conventional mortar now.

I am assuming that the patio is sound, It is monoblock and underneath it has been leveled with sand. It has been in place for 10+ years. What sould I be looking out for to make sure it is and what would be the alternative?

[Stuart Noble]

quoted text -

Jump up and down on it. If nothing moves, it's sound

[Andy Hall]

Look at the stones carefully and see if any appear to have moved. Jump up and down on it. You would see if it isn't sound.

[John Rumm]

I did mine using half bricks on dabs of mortar. I setup a rotating laser level and just used a ruler to measure down to each brick to get the height right on the mortar dab:

a long level on a few key bricks would work as well, filling in the others once the reference ones are in place)