Cut nails of tapered aluminium or mild steel form an excellent bond when driven into Thermalite. Helical nails also provide excellent fixing. Nails should be driven in at approximately 450mm centres and at least 75mm into Thermalite Turbo and 50mm for all other Thermalite products.
You can also fix heavy objects to Thermalite aircrete blocks using a normal high speed twist drill, not a masonry one, remove hammer action and use a proprietary wall plug. The secret is not to oversize the hole.