External Wall Insulation

We are a registered contractor with SEI to apply External Insulation for the £4,000 grant, our contractor ID number is 12378 Viking-House.

We have 7 years experience with External Wall Insulation in Ireland and our 1st External Wall Insulation projects are performing well with no maintenance issues or impact damage. We use a variety of insulation materials including Rock wool, Polystyrene and Wood-fiber board depending on the wall build up of the house being insulated but Polystyrene continues to be the most cost effective External Wall Insulation. We never use Polyurethane because the trapped Pentane gas which gives it enhanced Lambda values quickly migrates and PU is not breathable. We have unrivalled experience in dealing with Cold Bridges and tricky junctions for example where Glass porches meet the External Insulation. We have various window cill options and often use plastered EPS, Aluminum or floor tile cills.

We put External Wall Insulation on this cottage during the Summer/Autumn of 2006 giving it a facelift and substantially increasing its energy efficiency. We also built the 900ft2 rear extension with Poroton blocks and External Wall Insulation. The roof and floor were insulated at the same time and last year the now 2000ft2 cottage was space heated for just £350 worth of gas. We put External Wall Insulation over the window cills and fitted the new windows flush with the external wall and covered 50% of the frames with External Wall Insulation to eliminate Cold Bridging.

 

Before fitting External Wall Insulation to the cottage we dug a French Drain around the house in order to insulate the footings as our studies showed that the heat-loss at the wall-floor junction can be reduced by 80% by dropping the External Wall Insulation 500mm below the Floor level, the French Drain helped prevent rising damp by lowering the water table. We also connected the External Wall Insulation securely with the roof insulation to avoid Cold Bridging. A sheet of Woodfibre board was used at eaves level to stop the wind blowing into the soffet and through the roof insulation because roof insulation stops working when the wind is blowing through it. The vast majority of Irish houses have Cold Bridges around the windows/doors and where the wall meets the floor and roof. 2 inches of External Wall Insulation insulation works better than 4 inches of dry lining because it eliminates Thermal Bridges and reduces the risk of Interstitial Condensation.

Here are some of the Cold Bridges associated with the Traditional build that can be eliminated or reduced with External Wall Insulation installed in a correct manner by a knowledgeable contractor.

The Dew Point is usually in the middle of an uninsulated wall with a warm inner face and cool external. Dry lining shifts the Dew Point inwards to where the insulation and the wall meet making the wall cold. Polyurethane backed plasterboard lets Water Vapor through the joints which condenses on the Cold wall causing Fungus and Mould growth behind the Insulation. It’s impossible to prevent this moisture movement especially now that we have restricted Air changes, increasing the amount of water vapor in our houses. Timber joists that penetrate dry lining are especially at risk from moisture overload and wet rot. So the only safe option is to leave a ventilated cavity between the dry lining and the wall or apply External Wall Insulation.
BER Assessor