Over the past few years, we've published quite a few blog posts on the subject of slab lifting.  In this post, I'm going to highlight a few of our earlier articles covering some of the most common questions people tend to ask on the subject. Contractors who are considering getting into the business often wonder about the strength of polyurethane foam, where to look for lifting jobs, and how to estimate the amount of material they may need for a particular job.  Fortunately, we have thorough blog posts on each of those subjects.  

Slab Jacking with Polyurethane Foam – How Strong is Strong Enough?

When pumping a light-weight material beneath a slab, you need the confidence that it is strong enough for the application. How strong is strong enough? This is a commonly asked question by contractors that are new to slab jacking with polyurethane (poly lifting). Alchemy Polymers structural foams only need to be as strong as dirt, but they're actually stronger than crystalline bedrock.

Slab lifting foams are rated on density (weight per cubic feet) and compressive strength. This testing and rating is based on the foam in a free rise state; the parts A and B are mixed together and allowed to expand freely. Our AP Lift 430 and AP Lift 475 structural lifting foams, for example, will weigh 2.75 – 3.25 lbs (AP Lift 430) to 4.75 – 5 lbs (AP Lift 475) per cubic foot. But they have a compressive strengths of 50 psi and 100 psi in a free rise state. That's equal to 7,200 to14,000 lbs per square ft of support, just in a free rise state.

Read more in the post Slab Jacking With Polyurethane Foam – How Strong is Strong Enough?.

Identifying Common Markets for Slab Jacking with Polyurethane

Three main markets we will take a look at today include Residential, Commercial / Industrial, and Transportation.

The residential market offers tremendous opportunities for the slab lifting contractor. Obviously there are driveways and foundations. These can all sink for various reasons such as water runoff, excess weight, and poor compaction. But look a little further; this year alone we have had calls concerning the following areas: Patios, Outbuildings, Pools, and Porches. And don't think residential only includes houses. I'm not saying that construction companies that build condos and apartments would bury trash that would later cause settling issues; I'm just saying....

Read more in the post Identifying Common Markets for Slab Jacking with Polyurethane.

Estimating Materials for Slab Jacking

Jeff Foxworthy often asks if you are smarter than a fifth grader. Well if you're not, don't worry about it; you're probably still capable of estimating the amount of foam needed to raise a concrete slab. Through a combination of easy calculations, product information, and some site considerations, you should be able to estimate your slab lifting materials without too much trouble.

First of all you need to think about the basic volume calculation. How many square feet of slab are you jacking, how much do you need to lift it, and is it the whole slab being lifted or is it just one end of it? Calculate the volume (length x width x depth), adjust for the percentage of the slab being lifted, then compare it to the expansion properties of the injection foam in order to determine how much you need.

Beyond the geometry required to estimate lifting the slab, you must now take into account some job specific considerations. This is where it becomes critical to qualify the volume of material included in your proposal. And just as important, this is where you need to make sure you have included enough so you get the job done right and don't have to go back to the customer asking for more money. Sometimes that's unavoidable if you encounter surprises; but by keeping a few considerations in mind this can often be avoided.

Read more in the post Estimating Materials for Slab Jacking.

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