Unit 3 M3

M3

M3: Make and support valid decisions relating to the specification of materials for a tutor provided application

Introduction

By using the materials identified in P6 I can decide on which material is best suited for a foundation, building frame, guttering, external cladding of walls and wall insulation by looking at each materials properties and performance. This will help decide on which material is best suited for each component of the building as we will be able to find which material is the strongest and long-lasting for the foundation and which is best at stopping heat transfer for the wall insulation. For a construction project to be successful the right material needs to be used for each component in the building to ensure that the

Steel is more costly than e.g. wood which could have been used but it is longer lasting and is one of the strongest construction materials. It is a lot more fire resistant than wood as it melts at 1370 degrees Celsius while wood burns at 450 Celsius. Although more costly to install as it requires specialist equipment than wood which is a lot easier to install than steel and requires a less skilled labourer. Also steel isn’t renewable while wood is but wood requires more maintenance due to the different ways it is attacked. Wood can suffer from fungal attack; it also decays, and suffers from insect attacks while steel mainly suffers from corrosion. Due to wood having these defects it is a lot harder to control all of the different ways it can fail. So maintenance can be expensive. Also Steel does not break or shatter as it is the toughest material and is very hard wearing. Also Steel provides more sound insulation than timber due to the wood not being dense. Although a disadvantage of steel to timber is that timber construction is much quicker than building with steel. Overall I would use steel over timber on the frame due to its better performance and properties although it is more costly it will last longer than timber so is better long term than

Its thermal conductivity is 0.025 W/mK so very little heat is transferred through it. Which is needed as a building loses a lot of its heat through its walls. Polyurethane board also has a low moisture vapour permeability and a high resistance to water absorption stopping the water from being able to penetrate the walls and getting into the house reducing the chance of damp areas appearing. Different types of polyurethane board have different properties with some costing more than a normal board due to these properties. Some boards are able to contain fire resistant properties and others are denser making them stronger. The type of board I will be using has a density of 100 kg/m but will retain the same thermal conductivity but using a different grade of polyurethane foam that has fire resistant properties. This type of insulation has a relatively high compressive and tensile strength but during its production it does give off quite large amounts of Co2 and does contain toxic materials that could prove to be harmful to the surrounding environment. Although more costly the insulation having a higher strength and fire resistance will ensure that less maintenance will have to occur and so could be less expensive long