MRT Homes offers the client complete flexibility in frame specification, however the frame clients most frequently choose is a 184mm closed panel system.
With a 184mm closed panel system the external walls are fully fabricated within the MRT Homes factory, and are therefore delivered to site fully insulated, with electrical back boxes and conduit fixed within the wall panel in the appropriate places, the external Panelvent sheathing board and the inner face Fermacell wall board are likewise factory fitted. This frame affords the client many advantages. The first is that the frame by being fully fabricated off site means that there is less work required on site. Fixing wall boards and insulation on a work bench is considerably quicker and therefore cheaper than carrying out the same processes on site. The work is also carried out in dry factory conditions which are beneficial to frame quality. By spending more on the frame, the client will save money overall.
The size of the stud allows the panels to be highly insulated. Even using the cheapest form of insulation, glass wool, results in a U value well inside the latest Building Regulation requirements. It is worth noting that using a 90mm external wall stud, such as is employed by many timber frame companies, is actually more expensive in the long run than having a bigger stud. To adhere to the required insulation values 90mm frames have to be insulated with expensive rigid insulation boards such as Ecotherm, while the frame will also require an insulated external membrane. The wider stud also allows the client to upgrade the quality of insulation, or to use environmentally friendly insulation products.
The internal walls are usually manufactured using a 90mm stud, and the wall panels are delivered to site clad with Fermacell wallboard on one face only. This allows the client to fix electrical points and other services within the wall cavity. Once this work has been finisher the client then fixes the insulation for the wall panel and the fixing of the Fermacell to the unclad face.
The joist platform is formed using TJI I beams. I beams have a number of advantages over softwood joists. Being an engineered timber product the performance of the joist is known, and by selecting the appropriate beam size they can span up to 7 meters with no intermediate support. This can reduce ground works costs as supporting walls are kept to a minimum. The beams have “knock out” holes so that electrical cables and plumbing can be quickly and efficiently fixed. Finally, using I beams does away with the problem of squeaky floors.
Panelvent board is used as the exterior sheathing board because it allows the wall to breath, it eliminates the need to have an external breather paper, it has a high racking strength and lastly it is an environmentally friendly product moisture resistant.
Fermacell is used as the internal wall board because it has better sound deadening properties compared to plasterboard, the strength of the board means that fixtures and fitments can be fixed directly to the wall without any reference to noggins within the wall panel, and again it is an environmentally friendly product.
For structural beams that are exposed, such as roof ridge beams, MRT Homes use Glu-lam beams, with the client choosing the type of timber to be used. Hidden beams are generally Parallams, with metal beams only being employed if the depth of the beam needs to be kept to a minimum.
