How to Make a Glass Roof


Step 1: Prepare the site

Step 2: Build the canopy frame

Step 3: Place the rails on the frame

Step 4: Prepare the glazing beads

Step 5: Attach the glass frame

Step 6: Install the glass in the skylight

Step 7: Finish your skylight

Opt for a skylight to partition a room while bringing in light and preserving a sense of volume. Functional and aesthetic, it gives the room a trendy industrial look.

A real glass roof is made of steel uprights and glass panes that are higher than wide. To make a glass wall and give your home a stylish look, follow the step-by-step instructions. Even if you are not going to make it yourself, this post will at least explain to you the steps to follow so you can have an idea of what the contractor will be doing at your place.

Materials needed to make a skylight

Skillet bolt

Cartridge of mastic

Expansion dowel

Flat wrench

Scribing square


Gloves, mask and safety glasses

Adhesive joint

Tape measure


Spirit level

Paper + pencil



Electric mitre saw


1. Prepare the site

Determine the dimensions of the glass roof and the supporting wall

The easiest way is to install the glass roof on a plasterboard base.

– Determine the dimensions of the glass roof (width and length) and the dimensions of the supporting wall.

– Arrange the space of the glass roof according to the situation.

◦ If there is no partition wall, create the substructure to the desired dimensions.

◦ If the partition already exists, make the appropriate opening.

Good to know: in the case of a load-bearing wall, call a mason to put in the necessary reinforcements for the opening of the glass roof.

Draw the plan of the skylight

Determine the dimensions of the skylight windows and draw a plan.

– The windows should be taller than they are wide, but not too narrow either.

– Try to balance the number of windows with the width of the canopy.

For example, for a 150 cm wide skylight, you can choose 6 panes of 25 cm.

– Draw a plan of the canopy with all the necessary measurements.

Gather materials

Here is the list of materials you will need to make a skylight:

– 30 × 30 mm (or 25 × 25 mm) steel angles to make the metal frame, i.e., 2 angles for the heights and 2 angles for the widths;

– 25 × 25 mm steel tees to form the vertical crosspieces between the panes;

– 20 x 20 mm steel L-profiles for the glazing beads (profiles that hold the glass panes in the frame). Provide 4 profiles per pane (2 widths and 2 heights);

For example: for a glass roof with 6 panes, you will need 12 L-shaped profiles for the panes’ width and 12 profiles for the height of the panes.

– You can also use the glass panes of the desired dimensions.

Good to know: for more ease, have the panes cut in the store.

2. Custom metal frame of the glass roof

Check the squareness and dimensions of the opening

– Make sure the bottom and top of the opening are levels with a spirit level. Also, check the sides for plumpness.

– Check the squareness of the site by measuring the length of the diagonals with a string: they must be the same length.

– Finally, measure the height and width of the opening.

Good to know: the checks and measurements must be done accurately not to compromise the canopy’s installation.

Cut and drill the angles

– Transfer the measurements to the 30 × 30 mm angles that form the custom metal frame (2 heights and 2 widths of the opening).

– Cut the angles at a 45° angle at each end using a grinder and a protractor.

Good to know: you can also make the cuts with a mitre saw with a special steel blade.

– Check the cuts by assembling the 4 angle irons. They should form a 90° angle.

– For each angle, drill the part that will come to rest against the support using a suitable drill bit.

◦ On the 2 side angles, make holes every 20 cm or so.

◦ Drill about 3 holes per pane (space between crosspieces or vertical post). Please adjust the number of holes and their spacing according to the dimensions of your plan. 

Good to know: to easily drill an angle iron, place it on a wooden strip. This way, it will be held in place during drilling.

Weld the angles

– Assemble the first 2 angles with a welding magnet.

– Weld them together.

Grind the assembly to form good support for the glass.

– Do the same thing with the other 2 angles, then assemble the whole to form a frame.

3. Place the cross members on the frame

Cut and fasten the rails

– Determine the exact location of the vertical rails on the canopy frame.

– For each rail, determine the exact height inside the frame at its corresponding location and transfer it to the T-profile.

– Cut the rails to the desired height.

– Place and weld the rails one by one in the frame rebate.

Important: Make sure all T-profiles are positioned in the same direction to form continuous rebates with the frame profiles.

Drill the cross members

– Grind each weld to get a perfect finish for installing the glass.

– Drill holes in the rails on both sides at approximately 30 cm intervals. This will allow the glazing beads to be bolted on later.

Good to know: if you need to treat the frame or if you want to paint it, now is the time to do it!

4. Prepare the glazing beads

Cut the L-profiles

– Measure precisely the spaces for the glass panes (height and width) between the rails.

– Transfer these measurements to the 20 × 20 mm L-profiles.

– As with the angle bars, cut the profiles at a 45° angle to make the glazing beads.

– Check that the glazing beads fit together at a 90° angle.

Drill the glazing beads

– Drill the glazing beads according to their location.

◦ The top and bottom beads are drilled in the same locations as on the frame.

◦ Internal (vertical) glazing beads are drilled every 30 cm in the exact locations as the cross members to which they will be attached.

◦ The side glazing beads (on each side of the opening) are drilled every 40 cm (i.e., 1 hole out of 2, in the same locations as on the frame).

– Check the correspondence between the holes in the glazing beads and those in the frame and crossbars.

5. Attach the canopy frame

Glass Roof

Important: 2 people are required to complete this step.

Locate all mounting holes on the support

– Place the canopy frame on the bracket.

– Check that it is level and plumb with the floor.

Good to know: use small shims to help you adjust the level and plumb.

– Locate the mounting holes previously drilled in the frame on the bracket.

Position and screw the frame

– Remove the frame and drill the mounting holes.

– Place dowels adapted to the nature of the support.

– Present the frame again and fix it on its support :

◦ on the vertical uprights of the frame, fix 1 hole out of 2 (offset from the holes intended for the attachment of the beading);

◦ between the crossbars, screw only the centre hole.

6. Install the glass panes of the canopy

Apply adhesive seals

– Apply an adhesive seal to the entire inner perimeter (rebate) of the sash: frame and transoms.

– Also, apply a sealant to the glazing beads.

Install and fix the glass panes

– Place the first pane of glass on its location, pressing it tightly against the seal.

– While one person holds the glass, attach the top and bottom glazing beads to the frame using the free holes.

Install and secure all the glass panes in the same manner.

– Once this step is completed, attach the 2 side beads to the frame using the remaining holes.

– Then attach the inner glazing beads using bolts, which will go through both beads and the crossbar.

7. Finish your canopy

Apply an acrylic seal between the frame of the glass and the wall.

– Let it dry and paint it in the same colour as the glass if necessary.

– Also, paint the hardware if you wish.