Post Tension Roof

How to tell if you have a post tension slab.

Post tension roof.

For residential construction tendons at 48 inches on center are common. A good rule of thumb is that a post tensioned system will move about 1 inch for every 100 feet of slab that is not restrained by a lateral system. Commercial foundations will have much more steel. This hybridisation helps achieve the formation of a much thinner slab with a longer span devoid of any column free spaces.

Post tension slab is a combination of conventional slab reinforcement and additional protruding high strength steel tendons which are consequently subjected to tension after the concrete has set. Cables are arranged as indicated by the engineer and chaired to run through the center of the slab. Post tensioning is used to enable the floor and roof to achieve a level of water tightness and strength superior to that of regular precast concrete. Pt slabs offer the thinnest slab type as concrete is worked to its strengths mostly being kept in compression.

Many modern homes are built on post tension slab concrete. Construction of post tensioned slabs on grade is very similar to using reinforcing steel except for the tensioning step. A post tension slab is a concrete slab that has steel cables running through it that have been placed under 33 000 pounds of tension. A post tension slab is a slab of concrete that has been pre stressed using a specific method to increase the strength of the concrete.

Several methods exist for pre stressing concrete with post tensioning being a very common one. Post tensioned concrete slabs in buildings provide various benefits over reinforced concrete slabs other structural systems toward both single and multi level structures. Post tensioned pt slabs are typically flat slabs band beam and slabs or ribbed slabs. This tension makes the concrete slab and foundation much stronger than concrete without reinforcement and helps reduce cracking.

After decades of building and inspecting in the post tensioning pt concrete construction industry we ve seen the best and the worst of pt construction. In post tension construction tendons are placed prior to concrete placement and once the concrete reaches a specific initial compressive strength the tendons are stressed to a specified force and anchored. Post tension reinforcing is a method of construction used in the roof and floor panels of easi set and easi span precast buildings. Knowing the ways and the extent to which problems can occur helps us implement the most cost.

And we keep a long and growing list of the mistakes we ve encountered along the way.