Insulating materials

City & Guilds Construction

© 2013 City and Guilds of London Institute. All rights reserved. 1 of 16

PowerPoint presentation

Insulating materials

Unit 301: Principles of organising, planning and pricing construction work



Aims and objectivesAim:

• Introduce learners to estimating for insulation materials

Objectives:

• Explain why we insulate buildings.

• Evaluate the uses of thermally insulated materials.

• State where heat is lost in a house.

• Describe construction methods used to insulate against heat loss and gain.



IntroductionElectricity bills, oil bills, gas bills – all householders pay for one or more of these utilities, and wish they paid less. Often many of us do not really know how to control or reduce our utility bills. We resign ourselves to high bills because we think that is the price we have to pay for a comfortable home.

We are encouraged to turn off the lights and appliances, but may not recognise the benefits of insulating the attic.



Heating and coolingHeating and cooling (‘space conditioning’) accounts for 50–70% of the energy used in the average home. About 20% goes on heating water. On the other hand, lighting and appliances and everything else account for only 10–30% of the energy used in most residences.

It makes good sense to turn lights and appliances off when they are not needed, and you’ll save even more on your energy costs if you reduce the amount of energy needed for heating and cooling.



Why we insulate our homesInsulating your house helps to maintain a comfortable living environment by maintaining inside temperatures and reducing energy costs.

The main purpose of insulation is to create a barrier around the building – that is, over the roof, on the walls and beneath the floor – which reduces the amount of heat entering the home on a warm day, and also reduces the amount of heat lost on a cold day.

The diagram illustrates the different ways in which heat andcooled air are lost in a typical house.



Thermally insulated materialsPhenolic insulation

This provides maximum thermal performance with minimum insulation thickness, making it perfect for rooms where space is at a premium.

PUR/PIR insulation

Polyurethane insulation is versatile, lightweight and has high performance in thermal conductivity. Is used in cavity walls and floors.



Thermally insulated materials continuedGlass insulation

A range including glass wool insulation, Spacesaver rolls and cavity wall slabs for use in lofts, partition walls and timber frame constructions.

Rockwool insulation

Rockwool insulation has excellent thermal, acoustic and fire resistance properties and is suitable for walls, floors and roofs.



Thermally insulated materials continuedMulti foil insulation

• Easy and quick to install, multi foils require comparatively little space while also reducing radiant heat transfer effectively with polyethylene coated layers.

• Used under flooring, on roofs and around timber structures.

Vermiculite insulation

• Ideal for use as chimney backfill, pipe lining, roof and floor insulation.

• A lightweight, affordable, fireproof alternative to foam and earthwool.



Thermally insulated materials continuedAcoustic insulation

You can create a quieter environment using various acoustic insulation products for walls and floors.

Extruded polystyrene insulation

This versatile product can be cut to shape and installed in cavity walls and under floors to give acoustic and thermal insulation.



Thermally insulated materials continuedExpanded polystyrene insulation

Expanded polystyrene has excellent thermal insulation properties and is lightweight and cost effective. It can be used for walls, floors and roofs.

Vapour resistant insulation

Moisture vapour in rooms such as bathrooms can cause dampness. Vapour control boards can help prevent this problem.



Thermally insulated materials continuedCavity closers, socks and DPCs

PVC-U cavity closers are the simplest and most effective way to seal cavities around wall openings. Socks have acoustic properties.

Pipe insulation

This reduces heat losses by up to 87% and has Class O fire performance. It can be used to lag all existing exposed pipework.



Construction methodsStructural response times

The thermal performance of a building depends on:

• The level of thermal insulation, which affects heat loss.

• The thermal capacity of the construction, which affects the time the building structure takes to heat up and cool down .

• The position of the insulation, which affects the temperature profile through the construction.



Construction methods continuedLightweight construction

Lightweight constructions are those with low thermal capacity. They respond quickly to temperature changes in the surroundings. They are preferred in situations where heating is intermittent, because surface temperatures, which affect thermal comfort, increase rapidly.



Construction methods continuedHeavyweight construction

Heavyweight constructions (those with high thermal capacity, such as stone and brick buildings) take much longer to heat up. This can be useful where heating is constant (eg in hospitals) and in summer conditions, when heavyweight constructions can smooth out the peak afternoon outdoor air temperatures.

A heavyweight construction can be transformed into a lightweight one by the addition of insulation to the internal surfaces (dry lining of walls, carpeting, etc).



Construction methods continuedThe main construction methods used to insulate against heat loss and heat gain are:

• location of insulation

• selection of materials

• compliance with Building Regulations

• position of building

• position of doors and windows.



Any questions?

Education

Insulating materials