Step 3 placing the steel joists.
Concrete built up roof.
Built up roofing should not be applied directly to foam plastic insulations as referenced in nrca bulletin 9.
With the tilt up method concrete elements walls columns structural supports etc are formed horizontally on a concrete slab.
The forms are shaped and rebar cut to match final designs.
3 3 non nailable specifications are denoted by an i as the third character in the.
Often referred to by the acronym bur this system has been used for 100 plus years in the u s.
Two basic components felts and bitumen are laminated in the field built up to form a roofing membrane.
6 3 built up roofing over non nailable decks 6 3 1 these specifications are for use over any type of structural deck which is not nailable and which offers a suitable coating to receive the roof.
Even though a treated concrete slab is waterproof standing water on a roof terrace should be avoided and so all roof terrace slabs should be built with a small slope to ensure that all water is drained.
After the concrete has cured the elements are tilted to the vertical position with a crane and braced into position until the remaining building structural components roofs intermediate floors and walls are secured.
The bitumen serves as both the system adhesive and the waterproofing agent.
Next concrete is poured into the forms and finished.
These panels are created at the work site using wood forms rebar and concrete.
Exact specifications vary but most concrete roofs are several inches thick.
For example the florida based company hurricane proof systems offers a 7 inch 18 centimeter slab of concrete in three layers.
This normally requires the building floor as a building form but may be a temporary concrete casting surface near the building footprint.
They are known for providing excellent protection due to their redundant nature because they are made up of multiple layers of.
A built up roof system is a popular choice for buildings with low slope or flat roofs.
To install such a roof a crew first builds a framework for the intended roof.
Because typical concrete is porous it needs to be treated with an additive such as xypex which makes the concrete waterproof.
Built up roofing also called bur is the most common roofing material used on low slope roofs.
These specifications are not to be used over light weight insulating concrete decks or over a fill made of lightweight insulating concrete.
What makes bur systems so popular.
The bitumen is usually asphalt astm d 312 or coal tar pitch astm d 450.
The blocks come in several sizes but this guide will assume you are using a 16 3 4 inch wide concrete slab.
One of the most crucial step in building a flat concrete roof is to figure out the size of the concrete block you will need.
Bur is preferred for low slope or flat roofs because it creates a continuous sealed surface.
Tilt up construction features series of concrete panels tilted up into place to form a building s exterior wall.