How to Apply Lap Siding

How to Apply Lap Siding

Before you start nailing up siding boards, be sure to read through the information on preparing the wall. When you have the siding delivered, allow the wood to acclimate to local humidity. Store boards flat, raised above the ground on blocks or scraps. To make painting or staining the siding easier later on, prime or pre-finish it before installation and then touch up the cut ends as you work.

Plan your layout, and decide how you will treat the corners. When working out your layout, try to allow the siding boards to fit seamlessly around windows, doors, and other openings. With horizontal siding, a slight adjustment to your baseline may do the trick. Where you must butt board ends together, stagger the joints.

Nailing

Nail each board individually; do not nail through overlapping parts. Be careful not to dent the board's surface when nailing. Use stainless-steel, high-tensile aluminum or hot-dipped galvanized siding or box nails. Spiral or ring-shank nails offer the best holding power.

Choose nails that are long enough to penetrate the studs by at least 1-1/4 inches. Boards that are 6 inches wide and narrower require only one nail per stud; wider boards require two.

Cutting

Mark all 90-degree cuts using a combination square. Then do the cutting with a power circular saw, a handsaw, or (if available) a table saw or radial-arm saw.

First Board

The first board goes at the bottom. Most types require a 1-by-2 starter strip beneath the board's lower edge, along the wall's base, so the first board's angle will match the angle of the other boards.

Successive Boards

To lay out horizontal board siding, you will need to use a 'story pole,' made from a 1 by 2 that is as long as your tallest wall's height (unless that wall is more than one story). Make it as shown in Step 3 below.

Corners & Tops of Walls

When you are installing horizontal siding, determine whether the cornice will be open or closed before nailing the last board in place at the top of the wall. Where the boards must be cut at an angle to match the roofline, figure out and cut the angle as shown in Step 7 below.

Open & Closed Cornices

Cornices (sometimes called soffits) are often left open with wood-board siding so that the boards extend to the tops of the rafters. For this method, notch the board ends where they intersect rafters, and caulk the ends thoroughly once they are in place. Trim along the top edge, between the rafters, using quarter-round moulding or a narrow trim board (called a 'frieze board'). If you prefer a closed cornice, you can build one using a special wood board called a plowed fascia board plus roofing material. A plowed fascia board, nailed over the rafter ends or existing fascia, has a routed groove near one edge for holding soffit boards or panels.

1. Build a corner trim from a 1 by 3 and a 1 by 4, and then snap a level chalk line to indicate the top edge of the first length of siding. Next, measure down the width of your siding, and run a 1-by-2 starter strip along the wall's base to hold the first siding board at the proper angle.

2. Butt the first siding board in place against the corner, so that its top edge is aligned with the chalk line. Have a helper hold one end as you nail the other. Drive galvanized nails through the siding into the starter strip, spacing them 6 inches apart.

3. Make a story pole for transferring measurements from one corner to the next and to window and door frames. To make this, mark a 1 by 2 at intervals equaling the width of the siding boards. Then transfer these marks to each corner.

4. Overlap 1 inch of the first siding board with the second one, aligning the ends of the second board with the story-pole marks at the corners. Be sure the board fits snugly up against each corner, straight along its length and level, and then nail it in place. Place the nails about 1 inch up from the lower edge.

5. Repeat this process as you apply the other siding boards up the wall. Use the story pole to transfer the marks for siding placement onto the door and window frames.

6. Where two siding boards must be joined end-to-end, plan to center the joint over a framing member. Make very straight cuts to form a snug butt joint. Apply caulking compound to the board ends, nail them in place, and wipe off excess caulk.

7. If you'll be applying siding under gabled eaves (where the roofline is angled like the one shown), use a bevel gauge to establish the proper angle for cutting the boards. Transfer this angle to each board end, and then cut.