Build a Radiator Cover

Steam radiators are cast iron relics that heat brilliantly but look like industrial equipment bolted to your wall. A well-built cover doesn't hide the radiator so much as contextualize it—turning raw utility into something that belongs in a finished room. The trick is building a box that breathes. Hot air needs to rise freely through the top grille, cool air needs to enter from below, and the front panel needs enough perforation to let heat radiate forward without restriction. Get the venting right and you'll never know the cover is there. Get it wrong and you'll cook the paint off your woodwork while the room stays cold. This is a weekend carpentry project that lives at the intersection of function and finish, and when it's done well, the radiator becomes furniture.

1. Measure the radiator and plan clearances. Measure the radiator width, depth, and height from the floor to the top of the valve. Add three inches to width and depth for air circulation, and four inches to height so the cover top sits above the unit. Mark the baseboard behind the radiator—you'll need to notch your side panels around it. Sketch your dimensions on paper before cutting anything.
2. Cut the side panels and top. Cut two side panels from three-quarter-inch plywood to your depth and height measurements. Cut the top piece to your width and depth dimensions. Use a jigsaw to notch the bottom back corners of each side panel where they'll sit over the baseboard. Sand all edges smooth with 120-grit paper.
3. Build the frame structure. Attach the side panels to the underside of the top piece using wood glue and finish nails driven through the top down into the panel edges. Set the nails and fill the holes. This creates a three-sided box open at the front and bottom. Check that it sits square over the radiator with clearance on all sides.
4. Cut and install the front frame. Rip one-by-three pine boards to build a face frame that spans the front opening. Cut two vertical stiles to match the height of your side panels and a top rail to span between them. Attach the frame to the front edges of the side panels and top with glue and brad nails. This frame will hold your grille panel.
5. Cut and finish the grille panel. Measure the opening inside your face frame and cut a piece of decorative grille material to fit—perforated hardboard, metal mesh, or louvered panel. Paint or stain the entire cover and let it dry completely. The grille should have at least thirty percent open area for proper heat flow.
6. Install ventilation in the top. Drill a grid of one-inch holes across the back half of the top panel, spacing them two inches apart. Alternatively, cut a rectangular vent opening and cover it with a decorative grille. Hot air rises directly upward, so ventilation must be generous and positioned over the radiator body.
7. Attach the grille and set the cover. Secure the grille panel into the face frame opening using small screws or panel clips from behind. Lift the completed cover over the radiator and push it back against the wall. The weight holds it in place—no wall attachment needed.
8. Test heat output and adjust if needed. Run the radiator at full temperature for an hour and check that the room heats normally. Feel for hot spots on the cover—overheating means insufficient venting. If the top panel gets too hot to touch, drill more vent holes or enlarge the existing grille opening.