Thread: Fencing over a concrete surface

I would imagine that you'd bolt the posts to the concrete, not dig holes through it

How short is short?

If the gap between the house and boundary fence that you wish to close is under 2350mm, you should be able to mount the fence end on an existing fence post, the house end to the house wall, and cut down the panels and top/bottom rails to suit.

If you need longer, I would take the same approach and have a metalworker weld some base flanges to 50 x 50 x 3mm tube of suitable length, then have these powdercoated to match the panels or rails as required. The flanges can then be bolted to the concrete with dyna bolts to support intermediate posts.

For a gate maybe a metre wide, I would be cutting an opening in the concrete at least 300mm square, (increase with gate area), digging about 600mm deep, select a 75mm x 75mm x 3mm post of suitable length, and concrete (not quickset) it into hole, filling to finish flush with the existing concrete. Allow a couple of days to set fully. You can fill the post with a drier mix of concrete to increase rigidity if you wish. The post fill mix needs enough moisture to activate the cement properly, but should not be sloppy, as the mix will then shrink as the excess water evaporates.