High-Performance Bedding (HPB) is a limestone aggregate you can easily use for many DIY projects. It is 3/8″ clear stone with no fines and contains only pea-size pieces of limestone. HPB looks similar to limestone screenings but has been washed clean, and it makes a whole lot of difference. Limestone screenings wick the water away, especially if compacted. HPB, even in a well-compacted state, passes the water very well, as it consists of angular and not too fine particles.
For the areas with no heavy traffic, like a patio, High-Performance Bedding works great if you contain it by using edging. HPB consists of angular particles to interlock, so no shifting, no heaving, and the level of your patio will not sink, especially if you put landscaping or filtration fabric below the aggregate to prevent it mixing with the soil.
HPB is also a perfect drainage material under walls, slabs, and as a back fill around fiberglass swimming pools and behind small retaining walls.