We’ve working alongside many renowned architects, surveyors, engineers, electricians, plumbers, banks and insurance companies who all recommend timber frame as their preferred building method.
It takes just one Google search of “leaking ICF build” to see why despite being around for many years, ICF has not taken off.
There are too many unanswered concerns, few skilled trades and extortionately high costs for the potential return.
A Quick Cost Comparison
It must be remembered the cost to build an ICF home in Ireland typically excludes the roof. In comparison, our closed panel timber frame includes the complete design service, delivery, installation of the entire build structure and all associated costs such as steel and crane hire.
Our detailed quotes are returned within just 48 hours and include the timber frame structure, internal walls, first floor joists (solid or metal webbed joists), roof structure, roof covering (felt, counter battens, tile/slate etc.), breathable membrane, 140mm stud insulation, airtightness membrane and tape, with an additional 50mm of PIR insulation to the face of the stud (eliminating cold bridging) and finally 50 x 35mm battens to form a service cavity.
Our factory fitted service cavity allows first fix trades to commence straight away. All packages achieve a passive standard u-value, with a 100mm external leaf of block or cement boarded exterior, exceeding the requirements of both Part L and nZEB.
How Does Timber Frame Differ?
Timber frame is quicker to erect and much cheaper.
The cost is fixed and agreed from the outset.
You don’t have the same comfort with ICF as it’s highly dependent on the experience of the builder – and there’s not many skilled ICF builders in Ireland.
Disadvantages of ICF
- Lack of Skilled Labour
Although it may be advertised that the foam blocks are DIY friendly, it’s the pouring that requires the skilled labour.
You only get one chance to pour it right and the mix must have the right consistency.
Too loose and you risk blowing out a wall. Too thick and you’ll end up with air pockets because the cement will have trouble filling the forms correctly.
2. Build Limitations
Slight changes to your design or damage to the foam during delivery can cause problems.
Window and door sizes must be exact – you can’t just cut a wall and add a stud like you would do with timber frame.
There needs to be a very tight fit so it may be the case that some of the blocks need to be trimmed. If not done correctly, this results in a blow out from the form during the pour – not to mention delays and associated additional costs.
Whereas with timber frame, the entire build is pre-engineered in a dry factory environment. Any unlikely errors or changes to the design can be made at minimal to no extra cost.
Future renovation is also much more difficult and costly with ICF. Adding a window or door involves cutting into solid concrete for example.
3. Not Suited to Cold Climates
An ICF wall has half of its insulation on each side of the thermal mass of the concrete.
So when the heat you’ve paid for gets half way through the insulation, it gets to the concrete which transfers a large amount of your heat to the ground through the footings.
This is great in hot climates where you don’t want heat getting into the home, but its not so beneficial in our cold Irish climate where we don’t want our heat escapes from the inside!
We need as much insulation as possible on the inside to keep the heat in and a cavity to prevent cold, moisture and damp from the external elements. Concrete has no insulating value.
4. Low R Value
The R-Value of an ICF build is much lower than what most builders will tell you. Again, in cold climates like ours standard ICF insulation is incomparable to that of timber frame.
You can increase the R-Value by gluing rigid foam insulation to the forms but this adds significantly to an already expensive build cost.
It also takes away from your internal measurements. With timber frame, the insulation is packed within the stud frame.
5. ICF Negates Thermal Mass
What people often don’t realise is that when living in a well insulated, air tight home – you won’t be concerned about heating it in the colder months. You’ll actually be more concerned about cooling it in the hotter weather.
Timber frame is thermally responsive which means it heats quickly and also cools quickly when needed. It works very well with UFH.
Regardless, any benefit of thermal mass from the concrete is actually pointless with ICF as there’s foam on each side.
6. Moisture & No Cavity
Most of our clients have been told by their engineer to avoid ICF. One of the reasons being that it’s a single skin design so there’s virtually nothing stopping water soaking into the home through the concrete if the external foam leaf is penetrated.
There’s also a hundreds of Google searches about leaking ICF homes through the seams between the foam blocks. And because there’s no breathable cavity for the rainwater to run down like there is with timber frame, there are reports of leaking around the windows through to the internal walls.
The same thing happens with a full filled cavity in a standard block build. A cavity is there for a reason!
As the concrete blocks take a long time to cure, there’s also a longer drying out period and issues with condensation and the build-up of moisture.
Why Should I Choose Timber Frame?
With timber frame, some seem to be concerned about the likes of fire resistance and hanging photos or TVs on the walls – but the products used in timber frame are A1 Class fire rated. They go through the same fire safety testing as a block build and pass!
TVs etc. can be hung anywhere on the internal plasterboard (no need to hit a stud). GripIt fixings can take a weight load of over 100kg.
Still not convinced?
Have a look at our benefits page for more!