Trim-A-Slab is available in two sizes, 1" and 3/4" - and also in two colors, grey and black. For more information on this product choose from the selection below.
Trim-A-Slab is a replacement for rotted and old wood typically found between slabs in driveways and sidewalks. This wood was used during the slab construction, and is part of the ‘formwork’ used to define the size and shape of the slab. Once the cement had cured, it remained to accommodate expansion and contraction of the slab as it is heated in summer and cooled in winter. This wood then functions as an ‘expansion joint’.
Typical Slab Construction
The problem is what makes good formwork does not necessarily make a good expansion joint. The elements conspire to attack and destroy the wood, even if it was a rot resistant variety or pressure-treated to resist rot. Moisture allows bacteria to attack and break it down, movements open gaps which allow dirt and roots in, and eventually, the formwork looks a lot more like potting soil than wood.
What wooden expansion joints are faced with
Unless treated with weed-killers, your driveway can easily look like the one pictured below. Of course, chemical weed-killers are also undesirable, as driveways are almost always very close to storm drains. The best way to keep chemicals out of your local watershed and fisheries is not to use them at all.
A driveway gone bad
Trim-A-Slab is made from a rubber-like material that flexes and holds itself into the gap between concrete slabs. It is immune to rot, moves with slab expansion and contraction, and is not affected by moisture. It provides a redundant barrier to weed growth, and most importantly, does not trap dirt and debris like wood and other less flexible products. It will make your driveway easier to keep clean.
Trim-A-Slabs patent pending design is intended for slabs with radius (rounded) edges, and will fit and stay just below the surface without any special preparation The exposed surface is slightly recessed, and is resistant to damage from foot and auto traffic.
The clean, finished appearance is something your family and your neighbors will notice right away. It’s virtually maintenance free, and in case you need to run wires across your driveway for Christmas lights or an irrigation system, Trim-A-Slab can be removed and re-installed, no problem.
Trim-a-slab comes in black or grey. Choose black for the lowest maintenance and an accented appearance, choose grey to blend in. Grey will show tire marks after a while, but it cleans up easily with soap and water. Both are guaranteed for 5 years, so whichever look you prefer, you can be sure it will last.
Trim-A-Slab is available in 50 ft rolls, which only weigh about 10 pounds each, so if you do want to install yourself, it’s easy to handle. Visit the installation page for all you need to know about installing Trim-A-Slab. If you aren’t the do-it-yourself type, then visit the distributor’s page for a list of installers, who will take care of the whole job for you.
When it comes to expansion joint repair, there are a few options to consider. You can replace the wood with new wood, replace it with caulk, or replace it with a filler strip. Of these options, wood is clearly the worst. It is the hardest to fit back into the space, and there is no easy way to secure it. Any warping tending to lift it out of the joint will create a protruding trip hazard. All the same problems explained above with new wood remain as well, so weeds will establish themselves in the cracks, and in a few years the process will have to be repeated
The next thing to consider is the caulk-like repair. This method has a few issues as well. The material will fill the void space completely, which is good, but any subsequent caulk shrinkage or movement of the slab to open the joint will create a vertical crack. This crack then fills with dirt, debris, and finally weeds. The caulk-like fillers simply don’t have enough compliance to fill an expanding gap.
These materials also must be installed with some planning and skill. The depth of the evacuated joint must be closely controlled in order to be able to correctly estimate the amount of stuff needed to fill the joint. This can be done by back-filling the joint with sand, or by installing a filler strip which is pushed down to the desired depth. The filler strip is fairly easy to use, but the finished expansion joint is actually poorly supported, and can collapse down into the joint over time or due to foot or wheeled traffic. Lastly, the caulk-based repairs are a viscous sticky liquid which must cure. This means it must be installed carefully, and in a controlled manner to get a nice end product. The following instructions are from a tube of name-brand concrete and mortar filler and sealant:
Apply in temperatures over 40 F
Do not apply when rain or freezing temperatures are forecast
Joint should not exceed ½” wide by ½” deep
Allow to cure for 24 hours before direct exposure to water
Completely dry in 7-14 days
The best method is to re-fill the gap with a compliant filler strip. The more compliant the strip, the greater the range of motion that the joint can have without allowing dirt and weeds to accumulate. There are only a few choices in using this method, which is why Trim-A-Slab was invented. The other filler-type repairs which we have found to date are both Texas companies, and are vinyl products which are considerably more expensive than Trim-A-Slab. These products also have application instructions which require significantly more preparation than Trim-A-Slab. The depth of the joint cavity must be controlled, and it is recommended to fill with sand prior to installing their products. While these products are also ’removeable’, their installation guidelines include use of a hammer, so just how removeable are they?
We do recommend these products if your slab does not have a radius (rounded) edge, as they are the best option available, and they can be mixed with Trim-A-Slab in the grey color if you have some radius edges, and some sharp corner edges.
Trim-A-Slab is available in two colors, grey and black, both in a 50 foot long roll at hardware stores in many parts of Texas. Mail-order is available as well, should a retail store be too far. Trim-A-Slab is also available by the foot for direct pick-up at our League City distribution center, or through a distributor; please see the 'Purchase' tab for up-to-date maps of retail locations.
Current MSRP is given on the product data sheets, which are on the 'Products' page. Because Trim-A-Slab is a oil-based product, price does fluctuate. Please refresh your browser to be sure that the most current data is being loaded by your computer.
Just how easy is it to install Trim-A-Slab?
Trim-A-Slab pushes in by hand, or can be stepped on to install. It does not need to be driven or hammered into place. We have had Trim-A-Slab installed by kids under 10 years of age.
Do I need to use some kind of glue; how soes it stay in?
Trim-A-Slab grabs the inside edges of the slab during installation, and hold itself in. No glues or joint prep like back-filling is required. The 3/4" size is actually over 1" in width, so that when it is installed in a 3/4" gap it is in compression and squeezed down to the 3/4 inch size.
Can I get help installing Trim-A-Slab?
Absolutely. You can use one of our installers, or you can pick up some Trim-A-Slab yourself and use your preferred handyman.
How do I get the wood out?
This can be the hardest part if the wood has not rotted. We recommend prying it up from the ends rather than from the middle. If a piece is inaccessible from the ends, drill a few holes into it and place lag bolts into the wood, and pry up on those.
I ran into a nail, how to I get that out?
If you run into the occasional nail, a blow to the nail using a pry bar will typically shear it off or bend it out of the way. Trim-A-Slab is very compliant and can be easily cut with shears, so it is not necessary to remove all obstructions. You can cut away a portion of the underside of Trim-A-Slab to clear the obstruction.
Is there any real difference between the black and the grey?
All our products are made from flexible PVC, with UV inhibitors. Black is the choice if you want the lowest maintenance, as it will not show tire marks. Black will also make the concrete 'pop' a little, and make it look a little cleaner and brighter. The grey material is color-matched to concrete, and will blend in with clean, dry concrete. After a rain, concrete darkens, which will make the grey appear to stand out and look lighter than it really is. While the grey color will show tire marks, it is easily cleaned with soap and water.
What size do I need to use?
Most residential driveways and sidewalks were poured with a 1x4 or a 1x3 board used for the forms. These boards leave a gap about 3/4 of an inch wide, and will be by far the most common size. Use 3/4" Trim-A-Slab in these cases; you can make sure using our 'Sizing Guide' available on every page in the lower right side, in the 'Files' text box. 3/4" Trim-A-Slab comes in up to 50 foot long coils. This is the most likely way you will find it at retail stores.
In some cases, slab motion may have been significant, opening up slab gaps to 1" or more. Trim-A-Slab 1" is best suited for these applications, and it accommodates gaps from 7/8" to 1-1/8". 1" Trim-A-Slab comes in up to 25' continuous lengths.
Finally, 2x4 lumber is occasionally used as form boards. Trim-A-Slab 1-3/8" picks up where the 1" size leaves off, and will accommodate up to 1.5 inch gaps. 1-3/8" Trim-A-Slab comes in up to 25' continuous lengths.
What kind of warranty is there on this product?
Trim-A-Slab is currently warranted for 5 years. Trim-A-Slab will not crack, get brittle, or be adversely affected by heat or cold typical for a driveway anywhere in the US. Trim-A-Slab has been use from Minnesota to Florida. In fact, the flexible PVC material should be structurally sound for at least 10 years, however, we do not yet have 10 years of testing to back a longer warranty.
Where can I purchase Trim-A-Slab?
The 'Purchase' page has a map of stores that stock Trim-A-Slab. We are most often found in Ace Hardware stores.
For mail order, we ship using FedEx ground, and take credit card payments by phone. Thank You!
Download any of the files below for your reference.
Sizing Guide - 125kb PDF
Trim-A-Slab, 1-3/8 - 179kb PDF
Trim-A-Slab, 1" Product Info - 143kb PDF
Trim-A-Slab, 3/4" Product Info - 168kb PDF
Shipping Estimate - 194kb PDF
Mail Order Information - 335kb PDF
Expansion Joint Primer - 30kb PDF
Installation Manual - 1.8mb PDF