If you’re looking for a low carbon subslab insulation or green roof fill, and want to build foam-free, look no further than Glavel foam glass gravel. Made entirely from recycled glass, Glavel is a thermally insulating high performance aggregate that’ll streamline your job site and reduce the associated embodied carbon. While many contractors install the product themselves with construction teams, motivated DIY enthusiasts have also been able to install the product on their own with a couple of friends. With this guide, you’ll have step-by-step information to go from design, to delivery, installation, compaction, and finished product.
Steps to Glavel
Step 1. Dream up your project
Step 2. Speak with a Glavel representative
Step 3. Confirm payment and delivery date
Step 4. Product on-site arrival
Step 5. Truck unloading
Step 6. Install product
Step 7. Compact it!
Step 8. Lay slab
Step 1. Dream up your project
Whether it’s a slab on grade, deep retrofit, passive house build, or a deep foundation, Glavel is able to be spec’d in. The nature of the product’s aggregate pieces allow it to be used in a variety of manners, where it’ll perform with r1.7 per compacted inch. Consult with your geotechnical engineer for load bearing requirements and other structural considerations with your build.
Step 2. Speak with a Glavel representative for pricing and availability
Glavel representatives are always available to answer questions about the product, and will want to identify if Glavel is a suitable choice for your project. Details required for pricing and availability include: project timeline, square footage, desired r value, project location, and other notable considerations.
To speak with a Glavel representative about a project, click here.
Step 3. Confirm payment and delivery date
From there, the Glavel team will put together pricing for your job, which will include a price per uncompacted cubic yard, information guides pertaining to delivery, installation, and compaction, plus a rough delivery timeline. Typically, product lead time is 4-6 weeks for projects on the east coast, with an additional week of lead for west coast projects. As the date gets closer, the Glavel logistics team will confirm exact delivery specifics, pertaining to a delivery date and time, with other site features being taken note of, which will all be confirmed to the delivery driver.
Step 4. Product on-site arrival
Depending on the size of your job, Glavel will likely arrive on site in a 40 foot high cube container with 4 cubic yard bags (technically 3.92 cubic yards) held within. One container holds 19 bags, so if your job is less than that, you may be getting a split container with the extra bags being delivered to a different location after unloading. The corresponding number of containers will arrive onsite together.
Step 5. Truck unloading
The bags, also known as supersacks, have straps on top, which can be held and maneuvered by any sort of commercial machinery (Bobcat, front loader, forklift, etc.). Bags each weigh just under 1,000 pounds, and are 8 feet tall and 4 feet in diameter. Builders will often times rig some chains around the the straps, and then lift the chains with their machinery, which will offload the bags from the container. If not immediately installing the product, lay a tarp over the top of the bags. Glavel is closed-cell and water resistant, but keeping the product dry is ideal for installation.
Step 6. Install product
Prior to installing Glavel, a geotextile barrier must be laid below the layer where Glavel will be installed. Builders have found that Mirafi 140n works well with the product. In addition to straps on top of the bags, there is a cinch at the bottom, which can be opened at the proper time to install product into a foundation. Once bags are lifted, they can be held over the top of a foundation, and the product can be dropped in by releasing the cinch (see photos below). Leveling the product can be done with rakes to achieve a general flatness prior to compaction. The level should be done as accurately as possible, but the compaction process is forgiving and can correct any small errors of flatness from the leveling.
For more in depth information regarding Glavel installation, find our Installation Guide.
Step 7. Compact it!
Glavel compaction is done at a 1.3 : 1 ratio with a standard vibratory plate or site compactor. The compaction process provides additional thermal insulation (uncompacted Glavel is R1.3 per inch), improved load-bearing capacity, compressive strength, drainage capabilities, and a smooth layer upon which slab can be poured. The video below shows an install compaction, and more detailed compaction information can be found here. Glavel is capable of being flattened to + – 1 inch over a 6 square yard area.
Step 8. Lay slab
Upon compaction’s completion, the geotextile should be wrapped atop the Glavel layer, completely covering it. At that point, install can continue in the same fashion that it would with slab being poured atop the aggregate layer. Though this time it’s foam-free and built with an upcycled product.
