Does Durisol need a damp-proof course?

While a DPC (damp proof course) is not always necessary, UK building control division would always recommend that you have one to comply with Building Regulations within the UK. A DPC will prevent moisture rising through the poured concrete core and Durisol would be unaffected.

Can you fill Durisol with hemp?

Although in principle Durisol units can be filled with any substance, we do specify concrete as this provides the structural strength of the construction, as well as thermal mass benefits. No other economical poured product has the strength of concrete.

Does Durisol have cold bridging at the break in insulation?

Cold bridging does not occur as the insulation quality, R Value, provided by the width of the complete Woodcrete is similar to that of concrete and mineral wall insulation. A solid woodcrete unit 365mm wide would provide a U value of 0.22.

What is thermal mass and how does it work?

Thermal mass is the ability of a material to store heat (or cold). High thermal mass materials act as thermal sponges, absorbing and storing heat from the sun or heaters to release it at night. Yet, thermal mass is not a substitute for insulation as it generally stores and re-radiates heat. Insulation stops heat flowing into or out of the building. The right combination of these two elements, plus a building design that allows the capture of solar light and heat can improve the thermal performance of new buildings and lower energy requirements. The key benefit of Durisol’s Sustainable Construction Materials is that the majority of the insulation is located on the exterior of the concrete core.

Can I lay Durisol on top of existing brick and/or blockwork?

Although it is possible to build on top of existing bricks and blockwork with Durisol, the issue of shuttering the bottom course of the Durisol units and having the correct platform to work from would need close consideration. There also may be a need to take structural advice regarding the placement of rebar to the existing course. The key advantage of working with Durisol is the option to work below and above ground construction, so starting from the foundations would minimise the number of building elements required and the need for other trades.

Can I leave Durisol unfinished long term or do I need to cover it?

While Durisol can be left unfinished it is recommended that an external finish is applied, both internally and externally. Although the Austrian factory has remained unfinished for over 50 years, it is not a habitable space and the issue of dust and dirt retention is not a consideration.

Does Durisol allow water penetration?

Durisol units are made from 80% recycled timber that is specially treated not to rot or burn and in addition, not to support capillary action. This means it is not possible for moisture to be ‘sucked’ through the construction although it may allow water through if forced under pressure. It is recommended that an external rain screen is provided and wet plaster or plasterboard attached directly to the walling units either by ‘dot & dab’ or by screwing directly into the unit.

Is Durisol BBA Accredited?

Durisol is currently completing BBA accreditation, and confirmation is planned for early 2010. Durisol has BM TRADA, and ETA accreditation giving a CE mark. Durisol also has confirmation of compliance from Zurich Insurance Group.

Do I need to use concrete for the infill with Durisol?

As with hemp, Durisol recommends that you do use concrete for the infill. This will ensure that you gain the full benefits of the Durisol system, comply with the structural engineers and building control requirements, and do not compromise the structural integrity of the building.

Do I need to use rebar with Durisol?

You will need to ensure that you use reinforcement over openings to form lintels unless preformed lintels are used. While many builds in the UK up to two-storeys have no other reinforcement, each project will vary in design and structural requirements, therefore consultation with a structural engineer is needed in each case.

How does Durisol compare in cost against a brick finish?

Durisol compares favourably against all construction methods, and a brick finish is no exception. As of 2009, the average cost within the UK to have a block and brick finish supplied and installed is between £90-£120m2. Meanwhile, the average costs to have the Durisol system (depending on the unit required) supplied, installed, with concrete and labour included is between £60-£80m2, correct as of 2009.

The cost of material and labour aside, the Durisol system is also up to three times faster to build and is not dependant on the weather elements. Therefore, Durisol can offer major cost savings by speeding up build and reducing the contract period.

How does Durisol compare to Hemcrete?

Durisol is made from waste materials that will not rot or burn and provide excellent U vales for Eco Friendly Building. What’s more, the Durisol system can be built in all weather and quickly dries. Hemcrete needs to be constructed under controlled conditions and can take many months to dry out. The photograph below shows a home built with Hemcrete, six months after the building was complete and the occupiers had moved in