Dear Screwfixers, Once again kindly calling on the collective wisdom! I am renovating my ground floor flat in a 1950’s council block and am getting ready to put new floor down in two weeks time. Unfortunately due to the block’s communal boiler occupying a basement floor below my flat I experience both noise and unwanted heat at various times of the year. Because of this I had always planned to lay some sort of thermal and acoustic insulation to the concrete slab before laying an engineered wood floor. I am not expecting a silver bullet, but am hoping it will help reduce effects. The maximum thickness I could accommodate for the floor is around 50mm and in fact I had already planned a solution which had an entire thickness of 47mm and fitted a door frame to suit. That would have been… Scenario1 A. Engineered wood floor, 14mm B. Wood floor underlay, 2mm C. Celotex TB4025 (http://bit.ly/1QtH3NM), 25mm D. SBM5 sound matt (http://bit.ly/2g6xzwJ), 2mm E. SBM5 sound matt, 2mm F. SBM5 sound matt, 2mm Total thickness = 47mm However since this I have opted for a engineered wood floor which is 10mm not 14mm and crucially I understand from Celotex that I would need an 18mm T&G chipboard layer between the wood floor and the thermal insulation. This would make the total layer too thick (also adds additional materials and time to project)… Scenario2 A. Engineered wood floor (http://bit.ly/2g9LB2u), 10mm B. Wood floor underlay, 2mm C. T&G chipboard, 18mm D. Celotex TB4025 (http://bit.ly/1QtH3NM), 25mm E. SBM5 sound matt (http://bit.ly/2g6xzwJ), 2mm F. SBM5 sound matt, 2mm G. SBM5 sound matt, 2mm Total thickness = 61mm Celotex do a 12mm insulation board so have considered this, however I wonder if this is worth the hassle when thermal insulation halved… Scenario3 A. Engineered wood floor (http://bit.ly/2g9LB2u), 10mm B. Wood floor underlay, 2mm C. T&G chipboard, 18mm D. Celotex TB4012 (http://bit.ly/1QtH3NM), 12mm E. SBM5 sound matt (http://bit.ly/2g6xzwJ), 2mm F. SBM5 sound matt, 2mm G. SBM5 sound matt, 2mm Total thickness = 48mm Any thoughts or advice for a solution that is no thicker than around 50mm and ideally 47/48mm (will save me hassle adjusting height of door frame on already plastered wall)? I have already bought the engineered wood floor and the SBM5 sound matting so it is really the thermal barrier I need to think about. Scenario3 seems like best bet but wonder if Celotex at that thickness is really worth it. Perhaps a higher performing product at same thickness (though presumably more £££), or a thicker product specifically designed to be a top layer (with enough compression resistance to support T&G engineered wood floor etc.). Thanks in advance as always.
If its thermal insulation you want, I was thinking something similar to the airtec stuff I've installed in the loft - foil lined, thin but effective. Did a quick search and came up with this: http://www.builderdepot.co.uk/superfoil-underfloor-insulation-sfuf-1-5m-x-8m.html Its 6mm thick.
Does the soundmat have thermal insulating properties too? Have you though about splitting the soundmat - some below and some above the Celotex?
In my oppinion, it is thick. You can decrease from total thickness = 61mm to 55mm. You can search google to know more detail.