Frequently Asked Questions About Tilt-Up Construction.
Sitecast Tilt-Up Construction is a building method developed around 1900 where concrete walls or building elements were cast on site. However, Tilt-Up Construction is used more and more often for buildings and facilities in a wide range of industries. With over 15 years of experience in Sitecast Tilt-Up Construction, we received hundreds of questions. This is why we created this list with frequently asked questions about Tilt-Up Construction. Do you need to know more about Tilt-Up? We are more than happy to help you, take a look at the technical data of Tilt-Up Construction, technical data sheets & drawings or get in touch!
What is the typical thickness of a concrete panel?
Typically a concrete wall is 12-14 inches thick, this includes a 3 inch thick exterior face, 2-4 inches of extruded polystyrene insulation and a structural layer that is 5-8 inches thick.
What is the minimum size building that is economical?
A building as small as 5,000 square feet can be economical. Several small buildings clustered together may also prove economical. Special finishes on the concrete walls, such as exposed aggregate or form liners may make Tilt-Up an economical choice.
What is the minimum height building that is economical
Concrete panels up to 96 feet in height have been used in some areas, but special cranes and spreader bars are required for panels over 30 feet in height. It is generally better to have the panels all nearly the same height and less than 30 feet.
Are there any limits to the number or location of openings?
There is no real limit to the number or location of openings, but their location can be critical. Openings closer than the minimum from the end of the concrete panel supporting a concentrated roof load can add considerable reinforcing, thickened concrete or steel columns. The minimum distance is one-eighth the eave height, or two feet, whichever is less.
What size crane is needed to lift the panel?
It is best to let the crane company determine this, based on the size and weight of panels involved. A rule of thumb for the size, however, is two to three times the weight of the concrete panel.
Are there any site conditions that limit Tilt-Up?
Yes, the following should be considered: Access by the crane to the job site. Relatively flat terrain to allow the crane operation. Any power lines, ditches, railroad tracks, or other obstructions which limit crane operation. Other buildings very close to where panels must be placed.
What really holds the Tilt-Up panels in place?
The roof structure acts as a diaphragm to horizontally support the concrete wall at the top, and the curb on the footing supports it laterally at the bottom. The panels are generally not connected together to allow for expansion and contraction without cracking. The concrete panels are only positively connected to the roof at their centers near the top.
What information is needed to bid a building, and how long does it take?
With the preliminary floor plan, desired height, wall finishes, mansards, type of roof, preliminary soil report and building code jurisdiction may permit it to be completed in a week.
What information is needed to design and detail a building, and how long does it take?
The finalized floor plan, the soil report and decisions on all the bid options are needed, along with any planning commission requirements. With this information, the design and detailing for plans to submit to the building department will take a minimum of four weeks.
How do you insulate a Tilt-Up concrete wall?
Tilt-Up, much like most structural envelopes can receive insulation on the inside through the use of furring systems or the outside with EIFS. The most effective method of insulating Tilt-Up walls, however, is the method known as “sandwich”. This method is placing a layer of insulation between a structural concrete layer and an architectural or non-structural concrete layer during the casting of the panel and then tilting this entire construction as a concrete panel. This method is made possible by structurally connecting the two concrete layers through the insulation layer. As soon as the panel is erected to final position, the inside layer becomes structural and load-bearing, while the outer concrete layer is suspended from it to allow for temperature changes without cracking. It is critical that these two layers remain independent from each other except for the connection through the insulation.