Parts, boxes, rails and mounting · Rolling Shutter Guide
What size weather seal and rail felt does a rolling shutter use?
A rolling shutter seals in two places: a pile (felt) strip in the slat channel of each guide rail, and a seal along the underside of the bottom bar. On Roll-A-Shield shutters the rail pile comes in two heights, 0.200 in for mini and mini-wide rails and 0.380 in for standard and end-retention rails, on a 0.270 in backing.
Key facts
- Roll-A-Shield uses 200 felt in mini and mini-wide rails and 380 felt in standard and end-retention rails. Roll-A-Shield data
- The two piles are 0.200 in (5.1 mm) and 0.380 in (9.7 mm) high, both on a backing 0.270 in (6.9 mm) wide and about 0.03 in (0.75 mm) thick. Roll-A-Shield data
- Roll-A-Shield's current bottom seal fits all of its current bottom bars. Roll-A-Shield data
- The heavier single-wall bottom bar has a built-in seal about 3/8 to 1/2 in thick, used to close a small gap at the sill. Roll-A-Shield data
- A U-channel or L-angle at the sill helps seal the bottom but is not watertight. Roll-A-Shield data
Applies to: Rolling shutters of any make with pile or felt in the guide rails and a seal on the bottom bar; Roll-A-Shield mini, mini-wide, standard and end-retention rails and current bottom bars.
A closed rolling shutter seals along three edges: down each side, where the slats run in the guide rails, and along the bottom, where the bottom bar meets the sill. This page gives the sizes of the seals Roll-A-Shield uses and how to deal with the gaps owners most often ask about.
Where are the seals on a rolling shutter?
In the rails and on the bottom bar. Every guide rail has a channel for mounting it to the building and a channel the slats run in, and the slat channel is lined with weather stripping (plastic, felt or fabric pile) so the curtain runs smoothly. The bottom bar carries a seal along its underside that presses on the sill, floor or threshold, sealing the bottom edge against light, dust, drafts and wind-driven rain.
Two more parts help at the edges: a U-channel or L-angle at the sill, and the caulk run around the outside of the rails and box when the shutter is installed.
What size rail felt do I need?
It depends on the rail. Both of Roll-A-Shield's rail felts have the same 0.270 in backing; what differs is the height of the pile: "200" felt for mini and mini-wide rails, "380" felt for standard and end-retention rails.
| Rail | Rail width per side | Felt | Pile height | Backing width |
|---|---|---|---|---|
| Mini | 2.0875 in | 200 | 0.200 in (5.1 mm) | 0.270 in (6.9 mm) |
| Mini-wide | 2.638 in | 200 | 0.200 in (5.1 mm) | 0.270 in (6.9 mm) |
| Standard | 3.346 in | 380 | 0.380 in (9.7 mm) | 0.270 in (6.9 mm) |
| End retention | 2.944 in | 380 | 0.380 in (9.7 mm) | 0.270 in (6.9 mm) |
Both piles are black, on a backing about 0.03 in (0.75 mm) thick; the 200 pile is the denser of the two. These are the felts Roll-A-Shield now specifies; on an older shutter, or another maker's, measure the old strip's backing width and pile height before you order.
Which rail do I have?
Measure across the rail and compare it with the widths in the table above; a mini-wide rail is about 1/2 to 3/4 in wider than a mini rail. An end-retention rail is close to a standard rail in width but has three channels and a snap-on cover strip over its screw channel. The slat tells you too: 38 mm insulated slats run in mini or mini-wide rails, 55 mm insulated slats in standard rails, and 63 mm single-wall slats in end-retention rails. More on guide rail types and dimensions.
What seal goes on the bottom bar?
On current Roll-A-Shield shutters, one bottom seal fits every current bottom bar. It sits in a slot along the underside of the bar and can be removed and replaced. The heavier single-wall bottom bar is different: it comes with a larger built-in seal about 3/8 to 1/2 in (10 to 13 mm) thick.
Fitting a third-party seal is something to check with Roll-A-Shield first. For an older or other-brand bottom bar, send a photo of the bar's end so the seal can be matched; see Bottom bars (base slats).
Why is there a gap at the bottom or sides?
Match the symptom first; several of these are not a seal problem at all.
| Symptom | Likely cause | Fix |
|---|---|---|
| Even gap of about 1/2 in under a closed shutter | Seal worn, or too thin for the sill | A new seal, or, where it suits the curtain, a bottom bar with the thicker built-in seal |
| Gap under the bar, and the rails already touch the sill | Rails cut short when the shutter was installed | Call (480) 921-0200; it is an install fix |
| Motorized shutter stops above the sill | Bottom limit set too high | See Shutter stops too high, too low, or leaves a gap |
| Gap at one end only | Sloped or uneven sill | A custom bottom detail; send photos |
| Light or debris between rail and wall | Perimeter not caulked | Caulk with a paintable caulk, not silicone |
Does the seal make the shutter watertight?
No. The bottom seal and a U-channel or L-angle help, but they are not watertight; a U-channel can fill with water in heavy rain. See Do rolling shutters keep rain out?.
How do I look after the seals?
Clean the guide rails with a soft brush without dislodging the pile, and the rest of the shutter with mild soap and water, twice a year; no pressure washer; not in extreme heat. If the curtain drags in the rails, use dry silicone spray on guide rails only; never oil the motor or crank box. For squeaks and rattles, see Why is my shutter noisy?. Replacing the felt, the bottom seal and the plastic entry guides is covered in Replacing weather seal, entry guides and end caps.
Frequently asked questions
What is the felt in a rolling shutter rail called?
Pile weatherstrip, also called felt, brush seal, wool pile or weather stripping. It lines the slat channel of the guide rail so the slats run smoothly and the sides of the curtain seal.
Can I use the same felt in every rail?
No. Roll-A-Shield's two rail felts have the same backing width, but the pile height differs: 200 felt for mini and mini-wide rails, 380 felt for standard and end-retention rails.
How do I close the gap between the guide rail and the wall?
Caulk it. The last step of every Roll-A-Shield install is to seal the perimeter of the shutter with caulk; use a paintable caulk rather than silicone.
Should I oil the rail felt so the shutter runs smoother?
No. Use only dry silicone spray, and only on the guide rails; never oil the motor or crank box.
Parts and next step
Need a part or a hand?
Need rail felt or a bottom seal? Tell us the rail type (or its width) and the shutter height, or send a photo of the rail end. Call (480) 921-0200; the factory answers technical questions for any rolling shutter, not only ours.