Pre-Finished Aluminum Capping for Fascia Boards

The Problem It Solves

Wood fascia is the most exposed painted wood on a house. It runs the full perimeter at the roof edge, takes direct sun on the south and west, holds the eavestrough, and sits in the path of every overflow and spring melt. On homes from the 1970s through the 1990s the pattern is familiar: paint lifting at the bottom edge and the board ends, grey wood showing at mitred corners, and a repaint that has to happen from a tall ladder every few years and never seems to last.

The damage that matters is usually hidden. Water that overshoots or backs up behind an eavestrough soaks the fascia where the trough covers it, and the hanger screws give it a path into the wood. Ice along the roof edge in spring keeps that wood wet longer. By the time a homeowner sees a soft corner or an eavestrough pulling away, the rot has often travelled along the board or into the sub-fascia and rafter tails behind it.

Capping is the usual answer, but done carelessly it makes things worse. Aluminum wrapped tightly over wood that is already wet or decaying hides the rot and keeps it damp. Laps that face the wrong way, a bottom edge with no drip, or eavestrough screws driven through the capping without sealing give water a way in and no way out. Old capping can look fine from the lawn with soft wood underneath.

How It Works

The eavestrough comes off first, because the fascia behind it is where rot starts and where capping has to be tucked. Every run is probed along its length. Soft fascia, sub-fascia or rafter-tail ends are cut out and replaced with sound lumber before a single piece of metal is bent. Capping a board is only worth doing once the board is worth protecting.

Each run of capping is then formed from prefinished aluminum coil on a brake, to the exact depth of that fascia. The bottom edge gets a hem that laps over the soffit, so water running down the face drips off the metal rather than tracking back onto wood. Pieces overlap rather than butt, with each lap turned so wind-driven rain runs over the joint instead of into it, and so the metal can move with temperature without opening a gap. Outside corners are folded and overlapped rather than cut square.

Covered in aluminum, the wood is out of the sun and out of direct weather, and there is no paint on the roof edge left to fail. The capping is colour-matched to the eavestrough and soffit, and the eavestrough goes back up with its hangers driven through the capping into sound wood.

What Decides the Specification

Coil thickness is chosen by run length and fascia depth. Broad, flat sheet metal can show a cosmetic waviness the metal trades call oil canning, made worse by an uneven surface underneath and fasteners driven too hard. On long, deep fascia runs we use heavy-duty coil and straighten the wood beneath it; on short, narrow fascia, standard coil performs well. We don’t quote a thickness figure because it varies by manufacturer.

Colour and profile follow the rest of the roof edge. The capping should match the eavestrough and soffit, and ideally any window and door capping on the same house, so the exterior reads as one set of trim. Houses with a two-step fascia, a crown moulding at the roof edge or a steep rake need their own bent profiles, and those details take more brake work than a plain flat board.

Around Calgary

Painted wood fascia is typical of Calgary houses from the 1980s and 1990s, and often older. In the southwest, Shawnessy was largely built in that period, and its original wood fascia may have been through several repaint cycles. In the northwest, Varsity, Silver Springs and Dalhousie date largely from the 1960s and 1970s, and wood trim on those houses is older still.

Northeast communities of the 1980s and 1990s, such as Castleridge and Martindale, add hail to the picture: both appear on a 2025 local news list of hail-affected northeast communities, so dented capping and damaged fascia are worth checking alongside the siding. Airdrie, named in both the 2014 and 2020 storm reports, raises the same question.