Specify ventilation rates as a minimum of 1 sq ft 0 093 m 2 of opening per 150 sq ft 14 m 2 1 150 with a ratio of 1 300 in some conditions.
Roof construction methods.
Building codes in the u s.
The final price tag for a residential concrete roof runs pretty high often two to four times as much as a traditional wooden roof would cost source.
Next we ll examine various types of roofs and rafters and techniques.
Wind uplift is a concern for roof designers and much of the performance of trusses and other roof designs is down to how well the roof is secured to the building which is a site issue rather than a.
There are two basic methods of pitched roof construction.
But before discussing roof framing we will first review some basic terms and definitions used in roof construction.
The 3 most common materials used for flat roof construction.
Piece by piece rafter roof construction however is still the more common construction method for many buildings.
Hot tar and gravel.
Traditionally wall plates were attached to the wall by bolts a method still employed by some roofing contractors in addition to the straps.
Fundamentals of roof design and construction.
A wide variety of materials has been developed that will last many years in some cases as long as the house.
Ventilation of the roof deck speeds the evaporation of water from leakage or condensation and removes heat which helps prevent ice dams and helps asphalt shingles last longer.
This is more of a traditional manner in regards to cutting the timber while onsite and building up the roof by the use of rafters ridge boards joists and purlins among others.
Over the centuries roof building techniques have been refined to yield roofs of considerable strength and durability.
And homeowners have a vast selection of materials colors prices and other features from which to choose.
In many areas concrete roof construction also allows structures to bypass certain building codes and can also cut down on insurance premiums.
One pitched roof construction method is a cut roof method.
For that reason cold flat roof construction needs to keep in mind the need for unblocked airflow.
This can be determined by the size of the timbers or the size of the roof.
For example if your roof measures 10 feet 3 0 m x 10 feet 3 0 m and the slope of the roof is 12 12 giving a slope factor of 12x12 12x12 12 converts to 1 414 in decimal form you would multiply 10 x 10 x 1 414 to get the total of 141 square feet of roofing.
We will then discuss the framing square and learn how it s used to solve some basic construction problems.
A cut roof this is the traditional method of cutting the timber on site and building up the roof using rafters ridge boards joists and purlins etc the exact details being determined by the size of roof size of timbers etc.
