Aircrete for foundations? Absolutely says H+H Technical Director
Perhaps one result of aircretes popularity as an above-ground masonry material has been a lack of awareness of its suitability for use below DPC level. In the British construction industry, using aircrete as a foundation material is viewed as unconventional. The reality is that aircrete provides a simplified and cost-effective method of constructing foundations for residential properties.
In terms of strength, aircrete will not be left wanting as a foundation material.
A common assumption amongst contractors is that foundations need to have more strength than the superstructure above. However, it is in fact the lintel bearings where windows and doors are introduced to the wall structure which need the most strength. The loading is evenly distributed across the entire height of the wall below the ground floor DPC. This means that despite being one of the lightest forms of masonry, aircrete is fully load-bearing.
Because designers often assume that higher strength masonry units which are capable of sustaining their load at critical points must be used across the entire structure, aircrete is often overlooked for foundations. This can leads to an expensive over-design, as dense aggregate is used on the foundations instead.
Standard Celcon Blocks at 3.6N/mm2 are more than adequate for low rise housing, and we produce aircrete at a range of strengths to suit all sorts of other applications.
Because of its simple method of construction and lightweight properties, aircrete leads to less money spent on construction, which is beneficial to both contractors and end-users.
A recent Foundation Cost Comparison Study by Calfordseaden, an independent construction and property consultancy firm revealed that using aircrete for foundations on a three-bedroom semi-detached home could reduce build costs by almost 25%.
This is down to several factors. Because of its lightweight properties, aircrete can be laid extremely quickly. Combined with our proprietary mortar, an entire storey can be laid within a week.
Aircrete’s relatively fast build speed compared to dense aggregate leads to reduced labour costs, as less contractors can do the work in the same amount of time, or the same number of contractors can complete the works in even less time. Furthermore, the solid construction means that fewer building materials are necessary. These cost savings cascade down, saving money for everyone involved in the construction.
These are just a few of the reasons to use aircrete as a foundation material. Even before we take into account the outstanding quality of residential dwellings that aircrete is capable of producing, there are clear cost benefits to using the material which can be enjoyed by all involved with the project, contractor and builders alike.