Can I build it myself?
Yes, but its not something to take on lightly.
While putting together big "lego style" blocks may seem simple and fun, doing it correctly, quickly and safely, so that the concrete stays in the right place takes a bit more thought.
That's why we run two day training courses for new builders, which covers all aspects of working with the Logix system, followed up by support visits on site.
Alternatively we can put you in touch with a network of builders experienced in working with the Logix system who can tackle the project for you. For many people having someone come in and the get the build up to a water tight stage quickly and simply makes a lot of sense.
Is a structural engineer required?
Yes, he will need to do the structural engineering calculations for the design of the load bearing walls. Let us put you in touch with an experienced engineer.
Is steel reinforcement always required?
In many cases, in above ground structures, no steel reinforcement will be required, except over windows and doors. The decision of whether steel reinforcement will be needed is made by the structural engineer.
What is the specification for the concrete?
Above ground C20/25 is typically used, to give adequate protection to any steel used, while below ground C30/35 is more commonly specified. We try to keep the mix as standard as possible to help control costs. A typical mix would have less than 0.7% water and a target slump of 110-125mm, using 10mm aggregate. We recommended sourcing your concrete from an ISO 9002 quality-approved ready-mix supplier.
There are a number of different cement types on the market, which have different properties, in terms of how "green" they are and how they behave in the formwork. Using OPC (ordinary portland cement) gives a concrete that flows well, gains initial strength quickly once placed, and is is easy to work with. With more experience its possible to use blended cements which used recycled materials to replace some of the cement. Contact us for further information.
Do you need to compact (poker) the concrete?
Using forms made of EPS foam instead of traditional plywood does not alter the basic guidelines for placing concrete. Concrete can be compacted either by hand, with a steel rod, or by using an internal vibrating poker. To do a good job by hand takes a lot of effort, and diligence, and is only effective on small layers of concrete. The best method is to use the poker to compact the concrete, ensuring that the concrete entirely fills the forms and that the air within the concrete is removed.
Removing air trapped in the wet concrete is important for a number of reasons:
a) 1% of voids in the concrete equates to a 5.5% loss in strength
b) The life of steel reinforcement used to create lintels etc, is dependant on minimising the corrosion caused by ingress of moisture through voids with in the concrete.
c) unless otherwise specified the structural calculations will be based on the assumption that the concrete is properly compacted and void free.
Using a poker also has the following benefits:
d) It allows the use of a wider range of concrete slump, from 75mm upto 175mm, by improving the way stiff concrete flows locally.
e) It helps concrete flow into all the awkward corners and under windows cills etc.
The concrete Society, The Building Research Establishment and British Standards all stress the importance of proper placement and compaction of concrete.
Do I need an Architect?
As with any building project a good architect can really help you get the finished results you dreamed of.