Filling material differences?

[Sunetta]

Hi! 12 Dec

Anyone know the pros or cons of macadam vs drainage gravel? I'm building a new house and want to make a good choice!

MERRY CHRISTMAS to you

 

[Mats]

I want to recall that macadam is crushed and gravel is natural.

In any case, take crushed gravel as it settles better and becomes more stable.

 

[cy_berg]

I studied quite a bit before I started with my house foundation, and the reason why gravel is recommended is that it is capillary-breaking, which means it reduces or eliminates the foundation's absorption of water from the ground. Since we made our foundation with 200mm of cellular plastic insulation, we could basically have ignored this because 200mm of cellular plastic is considered capillary-breaking in itself. However, if you are going to make a foundation without cellular plastic/styrofoam, you should probably ensure that the materials you are casting on are capillary-breaking, which a sufficiently thick layer of gravel is. There are probably people here who can tell you much more about this than I can