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There’s no dew on Mars, what planet do you live on?

Saturday September 21 2019 BY ICOTHERM

Everything you need to know when selecting a solid roof.

There are a lot of lightweight tiled roof iterations out there, and beyond selecting a product for price there are several points that you should question when you are selecting the system you want to sit under.

Will my roof be prone to condensation?
Definitely not something you want to be dealing with!
So, you may have heard the terms dew point and interstitial condensation… but never really looked into what they mean. Now is as good a time as any….!
If there is one thing that cannot be avoided – unless you live on Mars, because there is no atmosphere out there – is that our air contains moisture. In the UK, average relative humidity (moisture) levels can be as high as 80%.
Dew is created when the air cools and moisture forms on surfaces as it can no longer hold onto that water.
Not much of a problem on the outside of windows, or even on roof tiles. More of a problem when this happens on the inside of the roof and creates interstitial condensation.
Interstitial condensation is formed when cool moist air (read: UK air) gets into the fabric of the roof and hits warmer air, or components that are warmer. If the temperature change is significant enough the dew point will be reached and form condensation that can eventually turn to mould and spread.

To make sure your selected solid roof will not create interstitial condensation
– Check that there is a suitable ventilation cavity to take out the moist air out of the roof, situated above the insulation and on the cool side of the roof
– Make sure the insulation supplied is sufficient to minimise any cold bridging and stop warm air from reaching the external rafter.
– If the system uses a cold bridging aluminium frame (unlike Icotherm’s roof): ask if that metal is suitably clad in non-conductive material to limit the possibility of condensation
– Check that the design specification includes vapour control barriers on the room side
– Check that the roof has successfully been through a CRA (Condensation Risk Analysis)

Doesn’t ventilation just mean draught?
A correctly ventilated solid roof will allow air circulation where it matters the most: well away from the room it sits on top of, right under the tiles and above the insulation. Check that the ventilation routes and vents on your Icotherm roof are not blocked. It will invalidate the manufacturer’s warranty.

Why clad-overs should be avoided – in our opinion
You might be considering a clad over as a low budget option; it has its place if:
– You are not looking to add value to the property or need Building Control approval.
– You are not looking for the best performing roof or the prettiest finish
– The insulated roof does not exceed the original weight it was designed for; roofs collapse are a thing.

So, the Icotherm roof system
The Icotherm roof system uses a solid roof construction, with 155mm EPS fully recyclable, rigid insulation, and is fully ventilated. It has been CRA checked and is Building Control compliant
Supplied in ready to “slide on” pods, which can be made to suit hard to access installation sites, such as having to go through the house (ie small pods), the Icoroof allows your preferred installer to replace / install your roof quickly and efficiently.

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