Frequently Asked Questions
AAC BLOCKS FAQ'S
- What is autoclaved aerated concrete?
- Can neolite AAC blocks be used in the construction of stem walls?
- Can this product be used for basement walls?
- Do AAC walls require insulation?
- How durable is AAC in various climates?
- Is a vapor barrier required in exterior applications?
Autoclaved aerated concrete (AAC) is a lightweight, precast building product used around the world. Available in blocks and in various sizes, AAC is an ideal material for structural walls, firewalls, soundwalls, floor and roof systems.
Yes, AAC may be used for stem walls. Stem walls should be protected against permanent exposure to water by applying waterproofing material such as bitumen coating on any surface in contact with soil. For exposed surfaces (above grade) that will be finished, use a cementitious waterproofing to improve adhesion of the finish.
Autoclaved aerated concrete walls may be constructed on top of AAC stem walls, concrete slab, or concrete masonry units.
Yes. The walls must be designed correctly to account for axial loads when used as a basement retaining wall. Due to the extreme horizontal pressures exerted by backfilling, thicker walls with additional vertical conrete and rebar reinforcement should be used, as specified by a qualified structural engineer. All walls below grade should be waterproofed as discussed above.
Almost never. neolite AAC walls are insulated by millions of tiny air cells which reduce thermal conductivity. The thick walls also benefit from high thermal mass, much like a log home. AAC block walls at least 8" thick typically provide sufficient insulation in southern climates.
Autoclaved aerated concrete is extremely durable. It does not rot or decay like wood or other organic materials. It does not rust like metal. Termites and other pests do not eat it. AAC will not burn. The millions of tiny cells in AAC cushion buildings from major force, preventing progressive collapse. AAC has withstood earthquakes in Japan, the frigid temperatures of northern Europe, the harsh salt air of the French Riveria, and the hillside fires of San Fransisco.
No. AAC construction provides a solid, monolithic wall system with an enclosed, non-connected cellular structure. Exterior finishes are designed to complement this structure, providing a healthy balance between moisture resistance and vapor diffusion. The positive pressure of the air conditioning system pushes water vapor out through the walls, while preventing moisture penetration from the outside.