Mike Montgomery from Modern Builds built and designed this project.
This is a low‑profile outdoor coffee table that mimics a white concrete finish while staying hollow and portable by using a wooden frame wrapped in cement board and coated with thinset mortar.
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Design
Mike aimed for a modern, low profile aesthetic that reads like poured concrete but without the weight and complexity of full concrete casting.
The design balances clean geometry with a slightly textured finish so the piece looks contemporary and handmade at the same time.
Frame & Joinery
The internal structure is a straightforward 2x lumber frame joined with glue and screws and reinforced with pocket holes to create a rigid shell for the cement board skin.
Mike added internal supports and a couple of center legs to reduce long‑span flex and to ensure the table feels sturdy enough for casual use on a deck.
Cement Board & Thinset
The frame is wrapped in half‑inch cement board, cut using the score‑and‑snap method to avoid dusty blade cuts and fastened like drywall with corrosion‑resistant screws and a small gap off the ground.
Mike applied multiple coats of white thinset mortar, using a notched trowel to establish even coverage and then smoothing and sanding between coats to build up a thin, nearly continuous concrete‑like skin over the substrate.
Finishing & Door
After sanding to remove high spots and feather transitions, the surface was sealed with a masonry/paver sealer to improve water and stain resistance while keeping the tactile feel smooth.
For access to the propane tank, a thermally‑modified ash door was glued up, sanded, and fitted into the opening with a simple finger hole, and small fit issues were repaired with glue and light sanding for a clean appearance.
Gas Insert & Safety
The project uses a drop‑in propane fire pit insert and a horizontal propane tank to maintain the low profile, and a metal face plate was installed for the regulator and igniter components.
Mike ran into clearance issues with the air mixer and lengthened fittings, but the tank fit when positioned at an angle; he emphasizes following manufacturer instructions and exercising caution when working with gas systems.
Lessons Learned
Thinset mortar can be an effective way to achieve a lightweight faux‑concrete look for outdoor furniture, but mix consistency and application technique matter a lot for vertical surfaces.
Early test‑fitting of gas hardware and being mindful of sanding materials (pigmented sandpaper can leave marks) are practical takeaways that make the build go more smoothly.
Overall, the project demonstrates an accessible approach to getting a contemporary concrete aesthetic without the complications of full pours or heavy forms.
Please support Mike by visiting his website: https://www.modernbuilds.com/.