What is ICF?

What is ICF?

ICF is an energy efficient building method which creates insulated structural walls for residential and commercial buildings.

For the Builder-Fast Track Construction – Speed of build is one of the unique selling points for considering a ICF solution. ICF is far faster to build with than Traditional brick & block or timber frame structures because it takes six to eight weeks from the time you place the order to the time the timber frame reaches site, during which an ICF structure could have been completed. ICF is available within three weeks and the concrete within 48 hours for reducing the critical path. House building has been steadily rising over the past 4 years but a current shortage of pulverised fuel ash (PFA) the waste product from coal fired power stations means that this key raw material for the production of most aircrete and concrete blocks could be dramatically reduced.

Reduced Labour Costs – Labour cost is much reduced over both traditional masonry and timber framing.

Less Down Time – Material availability is on short lead times.

Immediate Follow-On Trades –The ICF system allows the watertight building shell to be erected quickly. The follow-on trades can therefore enter the building and start putting utilities and finishes into place much quicker than traditional building methods.

Simple Service Installation – A great benefit of using ICF is the ability to put the conduit, cabling, ducting etc. For the services you require within the wall space of the empty ICF prior to pouring the concrete, this saves time and makes for a very efficient way of construction. This can be supplemented by chasing within the inner wall of polystyrene after the concrete wall has been poured and cured.

Less Heavy Plant and Equipment – Heavy plant and equipment that you would normally find on the average building site when using traditional building methods is not required with ICF. This is due to the light-weight nature of ICF and the quickness of the modular build. Naturally this also promotes Health and Safety on site.

Good House Keeping – Using ICF makes it very easy to keep the building site tidy and clean, as the ICF is easy to stack and waste is kept at a minimum and can even be used for insulating foundations.

Improved Site Safety – This is achieved by the fact that ICF is light to handle so less chance of injury. The work place is easy to keep tidy thereby cutting down the possibility of trips falls etc. and because the need for plant and other equipment is minimal, chances of accidents are also minimised.

Plasterboard – You have the ability to either fix directly to the plasterboard via the ICF dedicated fixing points alternatively it can be secured by using either battens or the “dot and dab” process. If a dry fix solution is used costs can be reduced.

ICF versus traditional build defects-The ICF structure can be built in most weather conditions including rain and frost and once the concrete infill is cured is not affected by adverse weather conditions. This is a big benefit to the finished job as alternative systems can suffer from extensive cracking, movement and defects once subjected to the same conditions.

Cost Savings – When all the factors and benefits are taken into consideration, ICF becomes extremely competitive compared to both traditional building methods and lightweight framing. Recent site examples have proved savings of between 25% to 30% in cost compared to traditional build and lightweight framing if a render is the external wall covering and a further 25% to 30% saving in build time against traditional where materials are on similar lead times. A similar timescale advantage accrues versus lightweight systems if the time starts from the date of frame order.

Low Running Costs – This is achieved when ICF is used to build the structure as they offer low ‘U’ Values from 0.20W/m2degk, down to 0.11W/m2degk and they actually perform to their ‘theoretical calculated design performance’ unlike most materials where a lower U value simply means an improvement on previous. Because dense concrete is the structural core and the layer of insulation is much thicker on the outer leaf (in the lowest U value requirements), “thermal mass” benefits are obtained which means that the building is warm inside when it is cold out-doors in winter and vice versa in summer. This means that you can turn your heating on later in the year and switch it off earlier. Because there is better retention of heat within the building, you are able to use a small boiler than you would have to had the structure been built out of lightweight materials and in some cases – Passiv-Haus Design, a boiler will not be required at all. As summers in the UK get increasingly warm, air-conditioning will increase but thermal mass will minimise the need for air-conditioning offering further savings against lightweight framed structures not yet taken into account by regulation but coming soon!

Good Acoustic Performance – Due to the density and thickness of the concrete cores within ICF excellent acoustic insulation is provided, well below the current Building Regulations Part E. Currently (November 2007) pre-completion tests are required since no Robust Details are in place for ICF’s but to date all tests with all ICF systems have passed the Building Regulation requirement.

Healthy Indoor Environment – An ICF structure will have minimal air leakage as it is a monolithic structure. North American experience demonstrates that occupants with allergies and chest complaints have minimal difficulties caused by dust, pollen etc. within the property than competitive house building systems.

Fire Resistance – All Insulated Concrete Formworks provide fire protection in excess of normal requirements. EPS (expanded polystyrene) is manufactured containing a fire retardant substance, which means the ICF does not support a flame.

Minimal Flood Damage – Concrete and construction grade EPS are unaffected by water. If ICF buildings are in an area which is subject to possible floods, they will withstand the pressure of water and flood damage will be minimised especially when compared with other building methods. ICF properties exposed to water can be pumped and dried out leaving the structure integrity unaffected.

ROT and Vermin – ICF structures do not rot and are unaffected by vermin and termites.

Wind Storm & Earthquake – ICF’s developed in North America as basement constructions providing successful protection from heavy storms and high winds including hurricanes and tornadoes. As market share grew ‘above grade’ there have been numerous examples where ICF houses have stood unaffected whilst lightweight framed structures have been completely destroyed. Since ICF’s are concrete framed structures, they can be designed to the relevant codes for earthquake zones if required.

Mortgage, Insurance and Planning Acceptance – ICF structures – concrete framed buildings – are accepted by all reputable companies and organisations as it has passed the recognised third party tests and standards that are needed to obtain building approval for BBA certification and ready-mixed concrete should be supplied from manufacturers offering BSI or QSRMC Quality Assurance schemes

Easily Adapted for Future Needs – Because ICF concrete frames offer a whole floor space without further loadbearing walls, it is easy to remodel and upgrade floor layouts in the future. The strength of ICF walls allow extra floors to be added subject to authority approval and it is easy to add and tie in future extensions. The structural walls also will accommodate extra openings in the future, though engineering approval would be needed. If even lower U values are required in the future, extra polystyrene could be easily fitted externally and reclad (although this is unlikely to be required due to the exceptional U-Values achieved by ICF).

Minimal Maintenance Required – Under normal circumstances no maintenance would be required on the ICF walls in the life of the building. The internal and external facades could be subject to minor damage which can be easily repaired or completely stripped and renewed.