The Strengths of Cellular PVC Siding

Synopsis: Cellular PVC is a widespread constructing materials, but is rather new as a siding. This write-up discusses the wood-like appear of cellular PVC siding as perfectly as the durability and resiliency benefits in places with weather conditions situations, as very well as specifics of one particular brand of siding’s interlocking joints and installation process.

Carpenters have applied mobile PVC trims for a long time, but as a stable and simple siding, cellular PVC cladding is a new progress. I to start with noticed mobile PVC siding in its early phases when developing-product or service manufacturer Westlake Royal asked me to arrange a personal assembly with architectural considered leaders Steve Mouzon and Andrés Duany. These two architects are very well recognized for their critique of vinyl siding, and the producer needed their sincere impression on a new class of PVC cladding. While the architects scrutinized and complimented the clear lines, crisp edges, and rigidity, I was fascinated by the rabbeted, interlocking ends and the idea that any plastic siding could face up to 210-mph winds.

What is mobile PVC?

In the developing planet, cellular PVC is a good plastic product, and it has been utilised for just about a few decades as a 100% artificial substitute to classic wood trim. “PVC” stands for polyvinyl chloride, the exact same materials used for DWV pipes as very well as vinyl siding (and lots of other creating products and solutions). Cellular PVC is a variety of polyvinyl chloride that is softer and a lot more flexible than conventional PVC. This softness signifies that mobile PVC can be molded to resemble true wooden without the need of emotion like plastic.

While not all vinyl is PVC, all PVC is vinyl, and the the greater part of vinyl items you come across in the creating earth are produced from PVC. PVC supplies incorporate additives that make them more robust, far more strong, and additional resistant to UV publicity and weather than other plastics. This is why PVC performs very well as siding.

Cellular PVC siding as we know it has been all over for about fifteen several years. It’s principally applied together the jap seaboard since of qualities that make it suitable for coastal climates, nevertheless its acceptance is expanding in the Midwest and South for the reason that of its sturdiness.

Image: Glenn Bashaw

Best of the wall

illustration of top of PVC siding

Trim details

illustration of PVC trim

Starter system

illustration of starter strip for PVC siding

Functioning in reverse

The largest adjustment to doing the job with cellular PVC siding is the order of set up. In contrast to other siding products, PVC siding is installed in advance of the trim. The to start with step is to put in furring strips or spacers all over openings and inside of and outdoors corners working with 1×2 PVC or taken care of wooden. Upcoming, put in the siding, allowing for a 1/2-in. to 1-in. hole concerning the boards and furring strips—a full inch if the operate is 12 ft. or for a longer period, and 1/2 in. if shorter. PVC claddings will need space to transfer as a end result of changes in temperature, and this hole permits that to happen.

securing PVC siding with stainless-steel roofing nails
Nail every single system. After a piece of siding is established in spot, safe it with 1-3/4-in. stainless-metal roofing nails pushed into the heart of the nail slot every single 16 in. and remaining a very little unfastened.
connecting two pieces of PVC siding
Slide in the joint. Every single piece connects to the piece to its left by using a rabbeted half-lap joint. Faucet the siding into position so that the bottom connects to the piece beneath.
secure top piece of siding with nails
Lock in the leading. Slash the leading study course to suit, and protected every single piece with nails placed together the reduce edge. The nail heads will hold the siding to the wall, and the shaft of the nails will maintain it locked to the siding below it.

A solution to thermal motion

Any mobile PVC siding requirements to clear up for the difficulty of thermal movement at the butt joints. During the seasonal fluctuation of summer and winter, PVC may possibly grow and deal as significantly as 2 in. in just a 12-ft. span. Suppliers get diverse techniques to locking butt joints with each other and accommodating thermal movement. The Westlake Royal Celect Cellular Composite Siding put in on this task makes use of a rabbeted joint tooled into the ends of each and every board. Gripping like interlocking fingers, this machined joint results in the operate of siding to shift as one particular piece from conclusion to close. And because the rabbeted union is exact, the seams practically disappear. Expansion takes place at both finishes of panel operates, with trim pieces covering any movement at corners and about windows and doors. This approach of interlocking would make the siding quite resilient after put in. Each and every piece of siding is entirely secured on all 4 sides, offering it unbeatable energy, particularly towards sturdy winds and storm situations.

Preassembled PVC trim

installing PVC trim around window
Preassembling cellular PVC casings and trim and installing them as a unit is less difficult and makes certain limited joints.
gluing and screwing PVC trim together
Implement PVC cement to pocketholed joints, and assemble with 1-1/2- in. exterior pockethole screws. For slim pieces, use PVC cement and CA glue (with an activator). The CA glue keeps the joint shut, though the PVC cement generates a long term bond.
Attaching the casing assembly
Connect the casing assembly to the spacers applying 1-3/4-in. colormatched stainless-steel screws.

(For additional, see Prefabricating Exterior Window Trim, FHB #260)

The numerous other positive aspects

As price ranges increase for other styles of artificial siding, cellular PVC’s up-entrance value has fallen extra in line with that of its rivals. Whilst cellular PVC is even now priced bigger than fiber cement, its installation price tag can be significantly reduced, building it an eye-catching choice. And like traditional vinyl siding, it is prefinished, small maintenance, and accessible in quite a few shades. (See a side-by-aspect comparison at the bottom of this site, with substance rates from my local dealer.)

Quite a few householders want the search of wood siding, but not the rate tag and routine maintenance. Vinyl siding accomplishes both equally goals for a minimal-expense installation, but cellular PVC seems, feels, and functions much more like wooden. It is accessible in a number of profiles for a additional customized exterior, such as regular clapboards with a sleek or wood-grain finish as nicely as shakes and vertical boards and battens. It appears to be convincingly like painted wooden siding, installs with standard woodworking applications and strategies, and lasts a prolonged time without having servicing. Most cellular PVC siding is warranted for at the very least 25 yrs.

With a mobile PVC siding installation, the boards stack on best of one a further, interlocking horizontally. The nail hem delivers oblong slots to heart fasteners. This built-in water management allows the product to go and breathe and produces a rainscreen cavity powering the siding significant more than enough to drain via gravity. For the reason that the joints of the siding aren’t airtight, the wall assembly at the rear of the siding can dry to the exterior. PVC absorbs no moisture, so it can scribe together a roof edge or stay in speak to with the floor with no causing destruction to the substrate or complete.

PVC is amongst the most quickly recycled plastics because of its straightforward composition—it’s made of just a single plastic as opposed to a mix of lots of. As an embedded plastic set up on a property (not a one-­use plastic that is discarded promptly, these kinds of as a h2o bottle), it does not conveniently pollute the ecosystem. And while recycling utilized PVC building materials is nevertheless a challenge in quite a few pieces of the place, the producing course of action for vinyl merchandise yields nearly no waste.

The small international warming possible of vinyl products and solutions helps make mobile PVC an attractive cladding choice to brick (which may have a for a longer time beneficial life but has a heavier up-front carbon footprint). If up-entrance carbon reduction and lengthy-lasting siding are a priority, wooden and vinyl claddings (such as mobile PVC) are great solutions. And cellular PVC lasts for a longer time and is more sturdy than classic vinyl siding.

If a woodlike aesthetic is the aim, cellular PVC siding is an approachable and progressively very affordable alternative. I am confident that stable, mobile PVC claddings—which are resilient, sturdy, and almost impervious to wind and hail—will come to be significantly popular as 1 of the very best materials decisions obtainable when balancing general performance and selling price.

Synthetic siding, side by side

chart comparing different types of synthetic siding

Fernando Pagés Ruiz is a builder and an ICC-accredited household constructing inspector in Houston. Images by the creator, apart from exactly where mentioned. Drawings: John Schreiner.

From Wonderful Homebuilding #315

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