Insulating A Flat Roof With Parapets

We also have a parapet on a flat roof and the ventilation solution is not through the cladding but the design flows air over the parapet.

Insulating a flat roof with parapets. Terminate roofing on parapet wall with mechanically fastened termination bar. For areas which do not need above cover hole with bug screen. Insulate within parapet wall cavity to depth of roof insulation if present. Parapets on modern roofs.

By majority the rule of thumb is that in a domestic house not flats approximately a third of the total thermal performance of insulation can be placed below the deck with two thirds above the deck sometimes this is called a hybrid. Screw it down and glue down a 45 mil epdm membrane. Upstands at parapets and abutments should be protected by either. I would switch to a warm roof insulation above the structural elements.

The parapet contains the sloped roof and frees up the architecture to have a perfectly flat profile. Naturally there are many different types of parapets for all the different situations materials construction methods and climates out there. The decks have been designed with parapets. Figure 5 ballasted inverted roof insulation over internal gutter figure 6 ballasted inverted roof detail at eaves pg 5.

The perimeter of the roof assembly insulation is wrapped to prevent interstitial airflow from the parapet into the multilayered rigid insulation of the field of the roof. Parapets can be both a safety feature designed to stop falls from the edge of the roof and also a constructional and stylistic feature a large percentage of flat roofs also feature a parapet of some height. The roof itself is therefore kept warm. Parapets often go unnoticed on modern houses as they can appear as the line of a flat roof.

When you sheathe inside the parapet hold the sheathing short enough at the top to install the same metal strip you use for gable vent. You nail the parapet studs right to the joists so if you have an 18 parapet on 11 7 8 i joists with 5 8 cdx over it you cut the parapet studs to 29 inch. Probably 1000 all put together for an r 49 roof in a 2x6 frame roof. Roof membrane must lap up wall to minimum of 12 above roof plane or per specifications whichever is greater.

The build is by mbc timber frame and it will be a cold roof construction. As with any building element when designing a flat roof it is good design practice to follow and adopt relevant design guidance. A warm roof is defined as being when the all or the majority of the insulation is above the joists or deck. Soooo then install the same perimeter wood blocking right over the roll roofing to match insulation thickness 5 or so of polyiso.