Pros and Cons
We'll tackle the 'cons' first because these matters are the reasons for problems with mortgageability of some steel framed houses (discussed below) and getting building insurance for them.
They also illustrate why, if you're a prospective buyer, you should always get a RICS home buyers survey before buying and, if you know that the property is made from steel frames, you should get a Building Survey.
Cons
- The steel components can corrode severely, particularly at the bases of the wall stanchions as well as the galvanised steel windows and the joins to the concrete ground floor slab.
- You often can't easily detect this corrosion and you can't inspect it unless you open up the walls via an intrusive inspection (i.e. not a standard RICS home buyers survey) and if you were looking to buy a steel frame home, the vendor might not agree to this.
- Steel houses suffer from relatively poor insulation and energy efficiency: steel conducts heat 300 to 400 times faster than wood and reduces the insulating properties of wall insulation by 60% because of thermal bridging (heat taking the most conductive path to dissipate: steel is an excellent conductor of heat. Additionally, thermal bridging can cause black stains to form on the cold portion of the walls.
- When you first look at the property, you might be unaware that it is built of steel frames and even less able to spot evidence of defects - unlike say subsidence and rising damp in brick-built houses - this is one of the areas where an experienced RICS surveyor can be worth their weight in gold.
- Steel framed houses are regarded as being of non-standard construction therefore when it is known that a building is made of steel, you need to get a Building Survey rather than a HomeBuyers Report because they suit the former survey's scope rather than the latter's albeit that a Building Survey costs more than a HomeBuyers Report.
- Special tools are required for maintenance; regarding construction, if for example you were buying a steel frame home kit, setting it up requires special knowledge and tools and it's very difficult to make any adjustments if there are any inaccuracies with the panels.
- Even a Building Survey - which is a purely visual, non-intrusive inspection, might not provide evidence of structural problems as there's no way of knowing if the body of the steel frames, if buried beneath layers of bricks/render, has been affected. For this reason, many surveyors might recommend a further intrusive inspection to provide a better insight into how sound the structure is, because they would not wish to give a 'green light' to a building which might suffer problems further down the line. Following from this, there is no reason why a vendor has to agree to such an intrusive inspection, although they might wish to in order to for a possible sale to eventually go ahead.
Pros
- Steel is very durable; unlike wood framing it doesn't warp or expand. It can withstand Level 9 earthquakes and hurricane wind speeds because it is flexible and can bend without cracking (plasticity).
- Steel copes better with water damage than wood, because it doesn't rot – how good its moisture resistance depends on its carbon content. Hot zinc coating and extra powder treatments for enhanced rust resistance will make a structural steel component even more immune to the effects of water.
- Steel is highly resistant to fungus. Woodworm and termites aren't an issue.
- Steel frame panels are grounded directly to earth - they are therefore highly efficient lightning rods for dissipating lightning bolts into the ground.
- Steel isn't combustible which might mean a discount on buildings insurance.
- Components can be quickly ready-made off-site then transported to wherever they're needed. They can be made in any shape and clad with any type of material and they can be joined together via bolting, welding or riveting. The frames can be rapidly assembled on site (with the right skills and tools).
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