Different Types of Exterior Siding and Cladding
Sometimes an exterior wall's structure provides the decorative finish, but most require extra material for decorative or weatherproofing purposes. For example, a brick or stone wall provides structure and finish, but a wood frame or block wall needs to be stuccoed or covered in siding. For most homeowners, the systems and techniques for these coverings become relevant only when they are faced with repairs. You will need to understand how these coverings are created if you want to match them on an extension, or if you wish to refurbish an entire section.
Things to Consider
Regulations and Permissions
The rules covering exterior alterations vary from area to area, and according to whether the building is in a historic district. Before your plans advance too far, check with your local authorities and homeowner's association as to whether you need permission. It may also be necessary to get permission to use certain paint colors.
Choosing the right exterior cladding material depends on your climate, personal preference, and budget. Follow all manufacturer's guidelines and local codes to ensure the material you choose performs well over time. One part of this is choosing the correct fasteners for the material and your weather conditions. Most often, you will need to use rust-resistant nails for exterior work.
This can be applied directly to blocks or bricks, or onto metal laths (sheets of wire mesh that help adhesion) to provide a decorative, weatherproofing coat that protects a wall's structure. There are several finishing options, including smooth stucco, the smoothest of stucco finishes with some slight texture (image 1); Patterned stucco, a smooth stucco that can be tooled to produce various patterns (image 2); Rough, a uniform rough finish that is applied over smooth stucco (image 3); and Pebbledash, which is achieved by throwing pebbles onto damp stucco (image 4).
Some topcoats have extra features, such as enhanced water-proofing properties, or suitability for finishing with outside-quality paint. Investigate your options with your builder or supplier, who will also be able to advise you on the quantities needed, and any waterproofing measures that may be necessary.
Planning to Stucco
Stuccoing large walls is not a job for an amateur—advanced plastering skills are required, as is experience in achieving the chosen finish. Unless you are very experienced, hire somebody to do the work for you. It may need several coats—usually an initial scratch coat followed by one or more further layers of stucco. Avoid application at times of extreme weather conditions, which can seriously affect the way stucco adheres, and may therefore reduce its life span. For those less experienced at DIY or the novice who wants the look of stucco, EIFS is an option. Made in panels, EIFS is similar to finished stucco and easier to install but requires careful flashing, so you will need professional help even for this option.
Siding is often found on most newer houses, forming the outer layer of a wood cavity wall. Some homes are partially covered in siding for decorative effect — boards can be placed horizontally or vertically — but siding also performs a vital weatherproofing function. Boards may be wooden, but synthetic options such as fiber cement board, vinyl, and aluminum are also available. These need less maintenance than wood, and some can be painted. Metal-based boards are usually attached to the house with special clips and channels, bought with the boards.
Siding should be applied on top of either building paper (a moisture barrier) or a breather membrane (which stops water from entering a wall, but allows vapor within the wall to escape). If you have a block house you may need a series of furring strips over the paper or membrane, to provide anchor points for the nails or screws to attach the siding.
Using Furring Strips
Horizontal siding goes onto vertical furring strips, which provide a cavity for drainage channels between boards and wall. To maintain channels behind vertical siding, which attaches to horizontal furring strips, fit vertical furring strips first. Chamfering the top edges of the horizontal furring strips directs water away from the wall. If untreated, furring strips must end 6 inches above the ground, so that siding does not touch damp soil. Use treated softwood measuring 1 x 2 inches. Some manufacturers will produce siding systems that incorporate an insulation layer between siding and the wall. Ask for professional advice, because it is important to use the correct insulation and vapor barrier to avoid problems with condensation.
Typically siding is installed from bottom to top, nailed to plywood sheathing through a building paper. Each product has its benefits and special installation instructions. These can include tools and techniques for making installation easier, and some require air spaces or nailing strips. Examples include, feather-edge boards with breather paper and vertical furring strips (image 1); tongue-and-groove boards with plyboard sheathing and breather paper (image 2); shiplap boards (image 3); and shingles with vertical furring strips beneath horizontal strips (image 4).
More Siding Options
Vinyl siding (image 1); brick (image 2); fiber-cement siding with plyboard sheathing behind breather paper and vertical furring strips (image 3); and tiles with horizontal furring strips (image 4).
Green Cladding Options
Consider green alternatives when choosing cladding for your external walls. Try using reclaimed wood, for example, or make sure that any new lumber you use comes from a sustainable source.
Aluminum cladding produced from recycled aluminum rather than a virgin source is another viable option. For clay tiles, visit a reclamation yard, as reuse is the most eco-friendly option and may save you money. While cement board is not the greenest option, if you are determined to use it, find manufacturers that use high quantities of recycled material.