DIY Doctor UK DIY Forums

Do I have to center a wall on the foundations?

It's a retaining garden wall, 1m high and 0.23m (9") thick. The foundations were going to be .6m wide but I hear from other posts on this site that you need just 100mm either side of the wall, meaning the foundations only need to be 0.43m instead of 0.6m.

However I was still intending the foundations to be 0.6m wide but put the wall nearer one edge than the other (as long as there is at least 100mm on the non-retaining side). That way I figure I can fit more rebar in the foundations after it has been bent 90degrees.

Will this design make any difference to the retaining strength of the wall?

The point of centering the wall on the footings (100mm overhang is a minimum) is to stabilise the whole footing in the ground so any ground movement affects the footing in the same plane. If the load is "lopsided" any shift in ground conditions will be exagerated in the wall because of the uneven loading.

eccentric loading to foundations is perfectly ok. Your wall at 1m high offers little loading to the foundation providing the foundation is adequate abd the ground below it ok. if its retaining wall you need to be more concerned about what it retaining and the wall standing up rather than the loading on the founds.