Warm Roof Construction Insulation Thickness

Hitting amazing levels of 0 13w m will need 300mm of mineral wool or 180mm of rigid foam.

Warm roof construction insulation thickness.

For a very good introductory overview article on r value see r values over at the website of. The roof insulation thickness will vary dependent on the required u value. If you are draining the whole roof to one corner you can try putting the firring pieces diagonally 45 deg across the roof joists. You should of course see the manufacturer provided technical data sheet for the r value of specific products.

The below table shows the thickness of insulation required for a typical warm roof construction with insulation fitted above the rafters. Insulating a flat roof with kingspan thermaroof. Our u value calculator is free and simple to use for calculating u values specific to your roof construction design. A warm roof deck is the most common and most preferred type of flat roof build up in the uk.

Or else on the interior of the building just. Thickness varies according to the manufacturer s specifications. R value of various materials. A flat roof where the insulation sits below the waterproof membrane and above the structural deck is a warm roof deck.

Warm deck the type of insulation for this is usually of a rigid type and the thickness will vary depending on the manufacturer s specifications. To comply with part l of the building regulations 2010 all roofs to rooms except those in unheated buildings should be thermally insulated to a maximum u value of of 0 18 w m k. See the department of energy s doe ranges for recommended levels of insulation below. This is placed over the roof joists and an board normally external ply is laid on top.

Of the insulation and tacked to the joists before applying the plasterboard. Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation. The sheets are laid at 90deg to the firrings. They increase in depth by a small amount each one say 1 8.

A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value. Thermoplastic or elastomeric are the most effective and should extend up adjacent walls at least 150mm from the roof surface. Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. Pitch roof u value 0 16 w m2k 2 warm deck pitched roof the insulation is placed over the rafters and then a felt is.

A thermal layer of fibreglass polystyrene or other insulating material should be inserted either above the roof decking the warm roof model which is suitable for homes or permanent residences.