Case study- Settled concrete with sub-grade point loads

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We come across two types of point loads, loads from above pushing down on the concrete and sub-grade supports that cause point loads when we attempt to raise the concrete. With this study we will be discussing the latter, sub-grade supports.

Last year we came across another porch that had settled even though the builder had installed Sonotubes or footers under the concrete to support the posts going to the overhead roofline.

This happens way to frequently and why we prefer the “big foot” style footers that flair out at the bottom as opposed to the 6″ 8″ or even 12″ Sonotubes with no flare at the base.

This porch had four Sonotubes and all had settled. Because of previous experience we knew not to attempt a lift unless we could disconnect the under slab supports. Fortunately the Sonotubes were partially exposed which enabled us to use a concrete saw on them which allowed us to raise the porch without damaging the slab.

Sub grade supports are a great idea but like most things need to be thought out and done properly to function as designed. Simply pouring a tube of concrete into the ground may not provide any support, in fact if not to load bearing strata it will exacerbate the problem. A small 6″ diameter Sonotube that is six feet long weighs roughly 1724lbs! Now imagine all that weight standing on its end and just six inches in diameter, it’s understandable that it settles.

Without being able to disconnect the support from the structure, whether it be a porch or patio, damage to the concrete is almost a certainty.

Experience matters, choose wisely, call today,

1-855-752-2522

www.SlabjackGeotechnical.com

Superior technology, Superior polymers, Superior results.

 

Case study – Raising settled interior concrete

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House floor slab with radiant heat
House floor slab with radiant heat

Pictured above is an interior slab with PEX water line radiant heat flooring. The foundation was allowed to sit uncovered for a year or so and with the large amount of snow and rain in this area, (Cle Elum, Washington) the floor settled about three inches in three areas, West, East and a breakfast nook area to the North. As I have mentioned in previous blogs, once settling occurs water flows to that area(s) and further settling is accelerated. In the picture you can see a square cutout for waterlines, there was an additional four inches of void in that corner.

1-855-752-2522 was called to do and estimate and determine the feasibility of raising the floor with PEX lines encapsulated in the slab.

It was determined through a pressure test that none of the lines had been compromised, further the home owner had a detailed layout of the position of the PEX lines. After reviewing the blueprint we were confident that we had a safety margin of about 8″ between lines in which to drill for the injection process.

To make sure we knew if a line had been breached the system was again pressurized prior to the drilling process. We drilled about fifty 5/8″ holes with no loss of pressure, installed injection ports and began the lifting process. Four hours later the job was complete.

Interior concrete often presents challenges like this one did. Other slabs may have carpet or tile or equipment that is bolted down or difficult to move.

Whatever the case, Slabjack Geotechnical is up to the task, call today, we can help.

1-855-752-2522

www.SlabjackGeotechnical.com

Superior technology, Superior polymers, Superior results.

Case study – Settled Concrete pool deck? arghhhhhh!

 

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As a concrete raising company we see a lot of settled concrete. Pool decks are some of the most challenging things we do, not that the slabs are different, they aren’t, the reason they are more challenging is the voids that develop along the pool even when the settling appears to be away from the pool and the precision needed to avoid creating additional problems.

As voids are filled, damage can occur to the structure of the pool itself especially on flexible pools such as vinyl or fiberglass. Gunite construction is much more robust so there is not as much concern with them but extra caution is always warranted when dealing with a twenty to forty thousand dollar pool.

How the pool deck was formed is always taken into consideration when writing the estimate. Was it laid over the wall of the pool or abutted, was bull nose tile used, how far away from the pool do the slabs go? Three feet or ten feet? It makes a big difference in how we approach the job and how feasible the job might be.

In the video below we raise a section of deck away from the pool and a section against the pool. Slabs not abutting the pool are generally just like any other walk with little risk of failure for the experienced contractor especially with the monitoring systems we have in place such as slope meters and lift gauges.

Narrow slabs abutting the pool like the ones in the video are often first raised into position with toe-jacks in order to minimize pressure against the pool wall and to avoid any lift at the pool side edge which would open up a gap allowing water over the top of the pool wall under the deck.

When pool decks settle as this one did, slabs often pivot which open up a gap allowing water to seep behind the pool wall which accelerates settling. When the deck is leveled this seam must be filled with pool caulk to seal out water or re-settling will eventually occur.

If you are dealing with this problem don’t trust it to novices, call the professionals,

1-855-752-2522

www.SlabjackGeotechnical.com

Superior technology, Superior polymers, Superior results.

 

Case study – Raising a sunken concrete driveway

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So, you have a settled driveway? We’ve raised a lot of them, here’s a video of one below.

The typical driveway settles against the foundation not the way this one did but either way the process is  the same.

Determine injection port placement for maximum material coverage and drill holes, cut slabs apart if binding is anticipated and inject material to gently raise the drive slab(s) back to proper grade.

On exposed aggregate with the small holes we drill, 5/8″ it will be very difficult to even see where they were patched as we blend color, tint and texture.

Because settling was severe on this driveway we shot additional material in from the side when the slab had been fully lifted, this ensured full coverage of the polymer and less possibility of re-settling.

Let us raise your driveway back to proper grade, eliminate trips hazards on walks and seal control joints and cracks. Call today,

1-855-752-2522

www.SlabjackGeotechnical.com

Superior technology, Superior polymers, Superior results.

Case study – wide but shallow Concrete porches that have settled.

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Wide but not deep porch "pinned" to foundation.
Wide but not deep, this porch is “pinned” to the foundation.

How porches settle and their dimensions even though the square footage may be the same greatly affects how much it will cost to level and the complexity of the job.

Take the above example; we have a wide but shallow porch which was pinned to the foundation. Though it appears to have settled only on the front you can rest assured the soil below the porch has actually settled even worse along the foundation of the home. In order to raise the porch the void has to be filled then the front has to be lifted as well as the space which will open up once the front begins to lift. A job like this can use three times the material the standard calculation calls for unless the void is taken into account.

Conversely a porch the same dimension just narrow but deep (opposite of the picture) is simple to raise and will use much less material to raise and support. Much like a lever helps lift something, raising concrete from the settled edge is much easier than the opposite.

We utilize the most sophisticated estimating software in the industry but it cannot replace an experienced estimator who has been in the field doing the work when faced with voids or obstructions.

Our estimators are our crew leaders and owners and while we do occasionally have one “get away from us” we make every effort to take into account every variable so material overages are held to a minimum. In addition, we discount material surcharges to about 45% of the original charge. If the estimate was $1350, double that amount of material would only add an additional $600. No one likes to see a surcharge and we work hard to avoid them and when we have to charge for one we only look to cover our cost.

We are a customer focused company, we treat our clients like we would want to be treated, fairly.

If you are looking for a concrete raising company look no further, we can help.

1-855-752-2522

www.SlabjackGeotechnical.com

Superior technology, Superior polymers, Superior results.

Case study- settled concrete patio

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Settled patio with trip hazards.
Settled patio with trip hazards.

Settled patios are a common occurrence, especially homes where gutters were not installed like this one.

On the example above we have two issues to resolve, first the two slabs abutting the home have settled, you can see how the steps have settled below the door frame. Second the other slabs are not in alignment causing uneven trip hazards. Both need to be corrected to have a level useable patio.

The above is very correctable and the roughly 225′ of concrete would cost less than eight hundred dollars to level. Replacement would run in the neighborhood of two thousand dollars, so for less than half of replacement this could be repaired in about two hours.

If you need your concrete patio, porch, driveway, walk or any concrete slab leveled call the concrete raising and leveling professionals today,

1-855-752-2522

www.SlabjackGeotechnical.com

Superior technology, Superior polymers, Superior results.

Heaved concrete – Case study

 

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image image

Hard to believe isn’t it? The top picture demonstrates what a tree root can do, the picture below show what Geo-polymer Slabjacking can do. Completely leveling three driveway slabs in about two hours. Can you see the holes after the job was done? They are close to imperceptible and they aren’t dry yet!

If you are ready to do something about your settled and uneven concrete but are shocked at replacement cost, call 1-855-752-2522 we can help.

1-855-752-2522

www.SlabjackGeotechnical.com

Superior technology, Superior polymers, Superior results.

 

 

 

The problem with pools.

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Pools, what a great way to spend a lazy summer day. Kids and Grand Kids enjoying the water, friends over for a pool party as you BBQ Ribs or Burgers, or just a relaxing evening enjoying the crystal clear water as the sun goes down. Having your own pool is a dream come true for many families, one that can build unity and be a gathering spot for family and friends for years, even generations to come.

Then there is the cost and hassle of chemicals and maintenance, all of which pales compared to the nightmare of settling pool decks. At 1-855-752-2522 we’ve about seen it all. Here are some things to know about settled pool slabs;

How we approach settled concrete slabs around pools varies with the type of pool, be it Gunite, Fiberglass or Vinyl.

Let’s first discuss Concrete or Gunite Pools;  these pools have the most robust construction of the three and are considered the safest to work on, having been constructed of a special concrete reinforced with rebar.

Typical deck construction on Gunite pools is to lay the deck over the top of the vertical wall of the pool, which is then caulked with waterproof pool caulking. This method leaves a very clean look with no bullnose tile to be found, though for aesthetics they can be used.

Settling occurs two ways. First, over time the caulking seal fails, allowing water penetration which leads to the compaction of fill dirt under the deck and along the walls of the pool, which over time, caves the soil in toward the pool and gradually leads to “pivoting” of the concrete deck.

The second area is on the outer side of the deck, where the deck meets grass. This settles slightly as water saturates the soils along the edge of the deck and grass junction. As this settles ever so slightly the slab pivots, opening up the caulk line allowing water to again, penetrate and further saturate and compact soils.

We have two good views and a video of a pool deck “pivoting” at www.SlabjackGeotechnical.com in the before and after pictures section as well as in the video section.

The diagnosis – if we were to completely lift the slab off the side of the pool you would find large voids along the pool, with the largest at the edge of the pool, even though the settling appears to be on the opposite, or grass side of the deck.

The cure – while the safest of the three, due to its robust construction, Slabjacking can exert tremendous pressures, thousands of pounds per square foot in some circumstances, not something we wish to have against the side of a pool. 1-855-752-2522 uses a hydrophobic Polymer (waterproof) that is injected and allowed to flow into the voids along the pool, consolidating loose soils and filling voids. This Polymer is very light, only four pounds per cubic foot but extremely dense so it is much safer than pumping a slurry which weighs between 100-140lbs per cubic foot against your pool. After these voids are filled any settling is taken care of on the opposite side of the slab.

Fiberglass and Vinyl pools are much less robust and as such, are approached much differently than concrete/Gunite pools. Due to the flexible nature of Fiberglass, and especially Vinyl pools, we do not attempt to fill voids along the vertical walls, doing so could bulge the pool walls and there would be nothing we could do about it after the fact. We will raise decks settled toward these pools only after extensive testing and then only with a disclaimer in the contract. Decks settled away from these pools are generally safe to raise and pose minimal risk of damage to the pool itself.

When it comes time to raise your pool deck call the concrete raising and leveling professionals 1-855-752-2522. Whether a Residential, Commercial or a Municipal pool, Slabjack Geotechnical is the right call – superior Equipment, superior Polymers, superior training, produces superior results.

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Slabjack Geotechnical Repairs a Driveway that had settled

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For about 1/2 the cost of replacement, 1-855-752-2522 can lift your settled concrete back to level grade. Here is a video of the process being done on a driveway which had settled roughly 2″

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Superior technology, Superior polymers, Superior results.