On our first log house we used hardboard – no felt, no breather membrane just hardboard with counter battens and slate battens on top of the rafters and paper under the rafters with counter battens. We pumped in recycled paper, then installed the pine t&g sheeting. This is an old fashioned Finnish method that we used because at the time we did not trust the so called breather membranes that were available. We inspected it after 10 years there is no condensation and it’s the driest attic we have seen.

We have since moved over to more modern products for a number of reasons. We feel that some of these now perform better and because we get so much rain, that before the roof is completed it is preferable to working inside without the fear of saturation and drips of water.

The roof in the first photo shows Solitec breather membrane over 200mm roof rafters with 50mm x 35mm counter battens and 75mm x 75mm battens for a corrigated  Duggan Corrifarm steel roof. Because the pitch is only 3 degrees we taped the membrane. This was to stop any condensation or wind getting under the laps. In fact because of the air gap there is no condensation on the underside of the corrigated steel. This is probabably my favourite roof and functions very well with 200mm of recycled paper pumped into the rafters. We used Pro Clima paper on the underside. Before we installed the pine t&g sheeting, we pumped in Warmcell recycled paper insulation. The second photo shows another house with a 25 degree pitch but I’m sure you get the idea.

Remember that some Irish county councils are really backward and even though a lot of old cottages replaced thatch with corrigated iron, two conditions you will see repeated are; cement render finish (CRH) and blue black slates (Tegral).

Ecological Building Systems

Duggan Profiles

Regards

Eamon Murray

Please Note: The Log House Company takes no responsibility for use of the above information. They are general guidelines and suggestions. Each project should be individually assessed.

 

Filed under: Log House construction in Ireland on April 21st, 2010