Upgrading insulation on a refurbishment roof

Increasing the thermal insulation within a roof makes perfect sense and has many benefits to the building, its reduction in energy usage for heating or air conditioning as well as supporting the environment.

Building regulations

Many current flat roofs will require the addition of insulation in order to meet current Building Regulations, and this is added ideally as the waterproofing is renewed.

Bauder can advise on the latest Building Regulation requirements, and make provision for the correct amount of insulation for your project within the bespoke specification that we provide. However, we would recommend that you seek confirmation of our advice from Local Authority Building Control (LABC) before submitting the specification for tender.

Cold roof construction

If the refurbishment project in question is a cold roof design, upgrading the insulation in the ceiling void is often difficult as it will be necessary to remove either the ceiling or the roof deck in order to achieve this. Once exposed, it may be discovered that the existing void is too small to take the volume of insulation required whilst continuing to maintain an adequate cross flow of ventilation above it. Even if it is possible to upgrade the insulation in the ceiling void, it will be impossible to provide a continuous uniform thickness, due to the presence of structural supports. Therefore a certain amount of thermal bridging will occur.

It is often preferable to convert an existing cold roof to a warm roof construction, as this greatly reduces the problem of thermal bridging. However, this will mean that any existing ventilation provision below the deck will need to be sealed off and there may be a requirement to remove any existing insulation from the void, as this could cause condensation problems.

The Bauder Technical Department is always available to provide specialist advice or undertake thermal analysis calculations should this be required.

Warm roof construction

In the case of warm roof refurbishment, it is likely that the level of existing insulation will not be enough to satisfy current Building Regulations. There are two common options; either to overlay the roof and introduce additional insulation, or to strip the existing system and start again. The first option should only be considered if the existing roof is deemed suitable and compatible for an overlay.

Installing a warm roof construction on a current building may create challenges, particularly if threshold heights are restrictive. The Bauder Vacuum Insulation Panel (VIP) is designed especially for installation on roofs or balconies where height is a constraint. BauderVIP is the thinnest and highest performing insulation within our portfolio, with the vacuum core achieving a thermal conductivity of 0.0072W/mK.

A profiled sheet metal roof can also be a challenge to upgrade the insulation on and for this we have an insulation overlay system whereby the insulation is manufactured to match the profiles on the roof and a sample created to ensure a tight fit before full installation takes place.

Detail design

Particular attention should be paid to the design of the new roof system to ensure that thermal bridging at perimeters and details is reduced as much as possible. Guidance on detail design is given by ‘Accredited construction details’ which is available from www.planningportal.gov.uk

Calculating the insulation required can be completed by our technical team as you may be considering adding to the values currently achieved or stripping off the current insulation and replacing with new, especially if any water ingress has occurred within the system and the insulant has become saturated.

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If you need to calculate how much insulation you need, just request a callback from one of our technical team or get in touch by phone.