Roof and Basement Insulation
Roof and Basement Insulation
The importance of a property’s roof and upper portions goes further than simply protecting occupants from rain and the elements on a basic level. Properties’ roofs and ceilings provide crucial insulation, influencing the air envelope and overall air tightness of properties. This can mean that the result of an air tightness test is affected by the roof.
Poorly insulated roofs allow excess heat to escape when trying to keep warm and in hot weather, a poorly insulated roof may not allow heat to escape. Not addressing the issues caused by poorly insulated roofs can lead to problems further down the line such as rising damp, mould and others.
When it comes to basements, not all properties in the UK have basements but they too can play a pivotal role in the insulation and maintenance of the property in question. Energy efficiency and insulation are closely connected, so as well as roof insulation, that of a basement is also key.
In both the case of roofs and basements, choosing the precise nature of either or both can have an effect on your property, so it is important to understand the implications.
Different Types of Roofs
When it comes to roof insulation, the kind that you will need will be dependent on the category your roof falls under. For example, if you have a flat roof, you can choose from an inverted roof, a cold deck, or a warm deck. If you have a pitched roof, you have two options to choose from: either a cold loft or warm loft insulation.
Flat Roof Insulation
There are distinct and also subtle differences with regards to which insulation you will need and this varies depending on the kinds of roof and property you have. Flat roof insulation for example, varies from pitched roof insulation:
Warm deck solutions – This is when there is insulation that is above the roof deck (this is the wooden panel underneath the roofing material.) It is usually recommended in areas that are particularly cold and damp.
Cold deck insulation – Cold deck insulation is usually situated just below the roof deck and the associated joists, leaving a gap so that there is ventilation. With this option, the roofing felt and bitumen will make the uppermost layer, helping to protect against rain fall (also known as the weather membrane.)
Inverted roof insulation – The insulation here is placed above the weather membrane. This means that it is protected from both the cold and heat, as well as general wear and tear. The uppermost layer with inverted roofs is usually made from gravel.
Pitched Roof Insulation
When it comes to pitched roof insulation, you have a choice between warm and cold loft insulation:
Cold loft insulation – This tends to be a popular option with people who have a pitched roof, as it is often the least expensive, and it also remains the only kind of roof insulation where you are able to apply for an insulation grant. Cold loft insulation is usually placed over as well as above the ceiling of the property’s top floor in between the wooden joists. This helps to prevent heat being lost from the living area of your home. It is possible to carry out cold loft insulation work as a DIY job.
Warm loft insulation – Warm loft insulation may be worth considering if you are using your loft as a living space, as cold loft insulation means that the loft will not be insulated in the winter months. In order to make sure that the loft is liveable when it starts to get colder, installing insulation directly under the roof in the plane of the slope can help to reduce heat loss, as well as preventing the roof from becoming uncomfortably hot in the summer too.
Considerations When Insulating a Property
As with cold loft insulation, you may also undertake this work yourself, but it is important to note that it is not as simple as laying rolls of insulation (as you do with the former option). You should also consider any potential implications on a property’s SAP and EPC as a result of insulation as properly implemented, insulation can increase the performance of both.
You will need to make sure you remember to allow for ventilation immediately below the roof tiles when installing a warm loft solution. This is because you could end up with condensation building up over time which could lead to the rotting of the roof structure and subsequent damage.
Often, the best time to undertake roof insulation is at the same time as you are replacing a roof in its entirety. However, it is possible for a roof to be retro-fitted, providing that is it is in excellent condition in the first place and whilst certain options provide the choice of carrying out the works yourself, it is recommended that you use the services of a professional installer, to ensure that the work is carried out correctly and efficiently.
Insulation for Basements
There are a number of different solutions you can choose from when it comes to insulation for basements and the precise type you undertake is dependent on the precise nature of your basement and the type of property.
External Property Insulation
Choosing external insulation for basements tends to be the most popular option, as it keeps the entire structure warm with a reduced risk of condensation. There are a number of things you should remember when it comes to external insulation though:
- You should make sure that the land around the building slopes away from the basement walls ideally if you are considering installing external insulation
- A drainage membrane should also be placed adjacent to the insulation, so that water can be channelled into the drain
- You should ensure that the external insulation has been placed against the waterproofing membrane
Internal Insulation for Basements
This tends to be an option used when it is not possible to utilise external insulation for a basement. In order for an insulation system to be placed directly within a property, it is important to make sure that:
- A cavity drainage system is used, as this can prevent warm air reaching basement walls and leading to condensation
- It is vital that any tears, perforations, joints and overlaps that are in a vapour control layer have been completely sealed with an aluminised tape
- There should also be the installation of a vapour control layer (this should be placed on the warm side of the insulation) as this can help to protect the basement also from condensation, as it prevents the water vapours from the basement walls becoming condensation