Rainscreen siding clips sit behind the cladding, holding the ventilation gap open so moisture can drain and dry. The clip is a small part, but it decides how well the wall sheds water, how much heat crosses the envelope, and how long the siding stays put. Before installing vinyl siding on a new wall or a retrofit, it pays to understand what the clip layer does and why material choice matters. This article covers how ventilated rainscreen walls work, the differences between nylon and metal clips, and the spacing and fastening rules that keep the system performing for decades.
How a Rainscreen Wall Works
A rainscreen wall separates the cladding from the water-resistive barrier (WRB) with a continuous air space. Rain that gets past the siding drains down the back side and out at the bottom, while air movement dries any moisture that lingers. Without that gap, water trapped behind the cladding has no escape route and the sheathing slowly rots. When you plan an exterior siding installation, the clip system you choose creates this space and keeps it open for the life of the wall.
Drainage and ventilation in one gap
The air space does two jobs at once. Drainage removes bulk water that penetrates the cladding, and ventilation moves air behind the siding to dry the cavity. Both functions need a clear path from top to bottom. Clips and furring strips hold the cladding away from the WRB, and their geometry decides how much open area the wall actually gets.
Minimum gap depths
Most manufacturers specify a minimum gap of 3/8 in to 1/2 in, and many code jurisdictions accept 1/4 in for some claddings. Deeper cavities, in the 3/4 in to 1 in range, give better drying performance in wet climates but cost more in furring and fasteners.
Clip and furring assemblies
Two layouts dominate. In the first, vertical furring strips run up the wall and clips attach the siding to the furring. In the second, clips mount directly to the sheathing and the siding snaps or screws into the clip face. The direct-clip approach is common with metal panels and fiber cement, while furring strips are typical behind wood and vinyl cladding. Both layouts keep the fasteners out of the water path, which separates a rainscreen from a simple nail-on installation.
Clip Materials: Nylon vs Metal
Clip material changes the thermal and mechanical behavior of the whole wall. Metal clips are strong and thin, but they conduct heat from the cladding to the structure. Nylon clips interrupt that path. Newer designs use 6/6 ballistic grade nylon, a glass-reinforced engineering plastic originally developed for armor and high-wear parts. Specifiers comparing engineered wood and fiber cement siding also have to weigh the hardware behind the cladding, because clip choice affects fastening, noise, and energy performance.
Ballistic grade nylon 6/6
Nylon 6/6 is a polyamide with high tensile strength, low moisture absorption, and good dimensional stability. In clip form it resists abrasion, dampens the noise of wind-driven rain and thermal movement, and adds almost no thermal bridging. The material also handles the temperature swings of an exterior wall without becoming brittle, which matters for clips that carry siding loads for decades.
Aluminum and stainless steel options
Metal clips remain common for heavy cladding and high-wind zones. Aluminum clips are light and corrosion-resistant; stainless steel clips carry the highest loads but cost more and conduct heat readily. Some systems add a thermal break, a small plastic pad between the metal clip and the structure, to limit heat flow. Steel clips can also rust where the coating is scratched, a real risk in coastal environments.
Abrasion, noise, and thermal performance
- Nylon clips do not scratch the siding during installation.
- They do not squeak as the wall expands and contracts.
- They keep the cavity warmer in winter by cutting heat loss at every clip.
Metal clips transfer heat at roughly 1,000 times the rate of nylon, so a wall with metal clips loses more energy at each clip location. For a typical house with several hundred clips, the difference is measurable but modest; for a large commercial facade, it adds up.
| Property | Nylon 6/6 | Aluminum | Stainless steel |
|---|---|---|---|
| Thermal bridging | Low | High | High |
| Abrasion on siding | Low | Moderate | Moderate to high |
| Noise dampening | Good | Poor | Poor |
| Corrosion resistance | Excellent | Good | Excellent |
| Relative cost | Moderate | Moderate | High |
Installing Clips and Furring Strips
Installation starts with layout, not fastening. The clip spacing must line up with the siding’s fastening requirements, and the rows must stay level across the wall. Much of the work on a residential project goes up with two or more people, but a growing number of jobs are handled by a single tradesperson, and the techniques for one-person siding work change how you stage clips and furring.
Layout and spacing rules
Mark the stud locations on the WRB first, then set the clip rows. Horizontal siding typically needs clips at every stud and at each end joint. Vertical panels need clips along every edge and at intermediate intervals, usually 12 in to 16 in on center. Check the siding manufacturer’s requirements before choosing spacing, because fiber cement and metal panels have stricter support rules than vinyl or wood.
- Snap level lines across the wall for each clip row.
- Locate the studs and mark them on the WRB.
- Install clips or furring, keeping fasteners out of the drainage plane.
- Verify the rows with a straightedge before hanging siding.
- Leave the bottom course open so water can exit.
Working solo: staging and hangers
A single installer can handle long runs of clapboard with simple jigs. Homemade hangers hold one end of the board while the other end is nailed, which removes the need for a second pair of hands. The same approach works for clips: pre-set the clips in a row, then hang the siding into them.
Fastener torque and alignment
Clips that accept screws should be torqued to the manufacturer’s specification, usually 20 in-lb to 30 in-lb for nylon. Over-tightening crushes the clip or strips the threads; under-tightening lets the siding rattle. Check every tenth clip with a torque wrench on the first wall until the feel becomes consistent.
Matching Clips to Siding Types
Different claddings load the clip system differently. Heavy materials such as fiber cement and stone veneer need clips rated for higher pull-out and shear loads, while lightweight vinyl and aluminum impose less demand. Cedar shake and shingle siding brings its own quirks: the courses are short, the edges are uneven, and the fasteners must be hidden or placed at the top of each course.
Vertical vs horizontal cladding
Horizontal cladding, such as lap siding and board and batten, uses clips that grip the bottom edge of each course. Vertical cladding, such as shiplap panels and metal sheets, uses clips that hold the panel edge. The load path differs: horizontal systems carry weight on the clips, while vertical systems mostly resist wind suction and thermal movement.
Shake, shingle, and panel siding
Shingles and shakes are installed course by course, with each row overlapping the one below. Clips for these materials must leave room for the overlap and for the slight warp that natural wood develops as it dries. Panels, by contrast, need full-edge support and often require clips every 12 in.
| Cladding | Typical clip spacing | Notes |
|---|---|---|
| Vinyl lap | 16 in on center | Loose fit required for expansion |
| Fiber cement | 12 in to 16 in | Stiff panel, full-edge support |
| Cedar shingles | Per course | Hidden fasteners at overlap |
| Metal panels | 12 in to 24 in | Edge clips, wind-load rated |
Corners and window transitions
Corners concentrate movement, so clips near corners should be spaced tighter than in the field. At windows and doors, stop the clip row at the trim and restart it on the other side, letting the flashing bridge the gap. Never run a clip through a flashing seam.
Rainscreen Performance in Practice
Once the wall is closed, the rainscreen’s value shows up in measurable ways. Buildings with ventilated cavities dry faster after wetting, stay warmer at the cladding plane in winter, and suffer less rot at the sheathing. The biggest gains come in wet climates and on walls with many windows, where drainage detailing matters most.
Moisture control and drying
Field studies and lab testing consistently show that drained and ventilated walls dry significantly faster than closed cavities. The drying rate depends on the gap depth, the vent openings at top and bottom, and the local climate. Even a shallow 3/8 in gap with open ends dries a wall several times faster than a cavity with no ventilation.
Thermal bridging and energy costs
Every clip that spans the insulation creates a thermal bridge. Nylon clips cut this loss to near zero, which reduces the heat transferred through the building envelope and trims energy costs. On a well-insulated wall, the clip layer can account for a meaningful share of total envelope heat loss, so the clip material deserves the same attention as the insulation value.
Comparing siding materials over rainscreens
The cladding itself changes how the rainscreen performs. Fiber cement and vinyl siding both work over ventilated cavities, but they behave differently: fiber cement is heavy and rigid, while vinyl expands and contracts with temperature. Each material has distinct fastening rules, and the choice affects clip spacing, trim details, and long-term maintenance.
Fasteners and Long-Term Maintenance
The clips are only as good as the fasteners holding them. Corrosion is the slow killer: a rusted nail loses grip, the clip loosens, and the siding starts to move. Ring-shank nails give better pull-out resistance in furring and sheathing than smooth nails of the same size, which is why they are specified for siding and clip attachment in high-wind areas.
Corrosion resistance
Hot-dipped galvanized or stainless fasteners are the minimum for exterior work. Electro-galvanized nails corrode quickly in coastal air and near treated lumber. If the clips use screws, choose coated or stainless screws and drive them into the furring, not into the edge of the board.
Inspection and replacement
Walk the walls once a year. Look for loose clips, cracked nylon, rust streaks, and siding that has worked loose at the ends. Replace damaged clips with the same material and rating, because mixing clip types on one wall changes the thermal and mechanical behavior unevenly.
When to replace clips
Nylon clips that crack at the mounting hole, steel clips with deep rust pitting, and any clip that has pulled away from the substrate should be replaced rather than re-fastened. The cost of one clip is trivial next to the cost of a siding failure.