When back-filling soil against a masonry wall, is it better to use clay or a sandy soil?

Question

Which would protect the foundation better from moisture infiltration? Which is the better insulator?

Answer 1

first make sure you have a water protector applied to the wall like tar,them a water proof membrane like plastic wrap or black bubbled plastic smooth side against the wall to drain the water away from the wall and to the weeping tile or drain pipe,should use a pea rock on the base 2 ft up and then sandy soil or preferably gravel again to help drain and keep water away from the structure NEVER NEVER NEVER USE CLAY IT IS THE WOST THING TO BACK FILL WITH IT WILL CAUSE YOU GRIEF AND DAMAGE THE WALL IN A MATTER OF TIME

Answer 2

Use sandy soil or even a coarser granular fill.

Soils with clay in them will retain water up against your wall and cause moisture to seep through.

Granular fill with sand will allow the water to drain through and not hold the moisture against your wall so it wont seep through and the interior will stay dry.

Answer 3

It is always preferable to use sandy soil rather than clay because of the favorable physical properties of the former and destructive properties of the latter.

Clay swells and shrinks depending upon the moisture content in it and this changing basic property of the clay will affect the stability of the civil structure.

On the contrary, sandy soil because of its cohesive nature, stores moisture content in its voids without any swelling until unless the soil is saturated with water content.

Further, the sandy soil is a good material which will disperse the superimposed and live load uniformly to the ground thereby preventing damage to the civil structure.