How To Insulate A Warm Flat Roof

When a homeowner really needs to cut down on costs some contractors may suggest the following.

How to insulate a warm flat roof.

You would only do this however if replacing the roof covering on top and you have the height above the roof to do this. In the case of a flat roof insulation is usually either a rigid board above the deck or a mineral glass wool quilt immediately above the underdrawn ceiling depending on the type of roof design and construction. With a warm roof the usual process is to split the insulation into two layers. Ventilation is necessary to allow moisture accumulated inside to escape.

How to insulate a flat roof. Like other roofs insulating a flat one requires ample ventilation a vapor barrier and sealed bypasses. Insulation can either be put below the weather proof membrane which is called a warm roof deck construction or above the waterproof membrane which is called an inverted warm deck. Insulation is placed in between the joists underneath the roof surface above.

Proper ventilation in flat roofs. It should be installed on tapered 2x furring strips in order to slope the surface of the roof to drains. In a nutshell you would sandwich 130mm of solid insulation between two decks allowing to place a vapour barrier on top of the first deck. Occasionally some ask for a new warm roof such as an insulated flat roof however the majority just want a.

Many times i answer the phone and customers ask me to give a price for a new flat roof. The correct method for a flat roof is under the current regulations to have a warm roof. The only point of putting the insulation on top of the waterproof membrane is when you can t take it off as when for example it is bitumen. It also lets hot air escape in the summer.

Add an additional layer of osb over the sheathing. If 180mm is to be installed then 100mm board might be introduced between the rafters there has to be a minimum 25mm air gap between the insulation and the underside of the tiles or slates with an 80mm board running across the rafters. Both these variants require different approaches to insulation which will be covered in this guide.