Start with the honest answer: try a stock vent first
If you're replacing a cracked or missing floor vent in an RV, camper, or mobile home, check the standard sizes first. RV floor registers are commonly sold in sizes like 2" × 10" and 2-1/4" × 10", and those are inexpensive stock items at RV supply stores.
If one of those fits, buy it. A custom register only makes sense when the stock ones don't.
When stock RV vents don't fit
You may need a custom size if:
- The floor was modified. New flooring, a remodel, or a repaired subfloor can leave an opening that's a little larger, smaller, or out of square.
- The style is discontinued. Older units sometimes used registers you can't find anymore.
- The opening is just odd. Some units used unusual sizes from the factory.
- A stock vent fits loosely. It drops in, but rattles or slides around.
That's where our Custom Size Floor Vent Register comes in. We update our 3D model to your measurements, print it, and ship it.
How to measure an RV or mobile home floor vent
The rule is the same as in a house: measure the hole, not the cover. Registers are sized by the duct opening, and the faceplate is always larger.
- Lift out the old register. Remove any screws first.
- Measure the width of the opening, inside edge to inside edge, in two places.
- Measure the length the same way, in two places.
- Use the smaller reading from each pair.
- Round to the nearest 1/16". Don't round up to the next whole size.
- Check whether it sits flush. If the register drops into a recessed pocket, also measure the pocket's width, length, and depth.
- Take photos of the opening with the tape measure in frame, plus the old register.
For a full walkthrough, see how to measure a floor register. To see how nominal sizes relate to real openings, read floor vent sizes explained.
What we can make
- Width: up to 6", which covers the narrow registers common in RVs and mobile homes
- Length: no set limit, though registers work best at 16" long or less. Longer is case by case, so ask us.
- Material: PETG for RVs and campers (see below). Our standard registers are PLA, so request PETG in your order notes or through our contact form.
- Color: Black, White, or a Custom Color of your choice, including glow-in-the-dark
- Price: from $35, varying with the cost of the plastic
- Lead time: about 1–2 weeks, since each register is made to order. If you need it sooner, use our contact form.
Why we recommend PETG for RVs and campers
PLA is not recommended for RVs. PLA can soften and bend in a hot, closed-up camper, such as one sitting in summer storage or parked in the sun. A register that warps won't sit flat or fit its opening.
For RVs and campers, we recommend PETG instead. PETG is another common 3D printing plastic, and it generally tolerates heat better than PLA. When you order, ask for PETG in the order notes or contact us before you buy.
Whatever the material, keep printed registers away from furnace outlets that run very hot.
A mobile home that stays heated and cooled like a house is closer to a regular home setting. If yours sits closed up in the heat, treat it like an RV and request PETG.
Limits to know before you order
- No direct foot load. As the product page notes, plastic will likely be weaker than metal or wood, and we don't recommend direct loading. RV and mobile home floors are small, and vents often end up in the walkway. If yours is somewhere people step all the time, a metal register is the safer choice.
- No dampers or louvers. Our registers don't include them.
- No returns. Each register is custom-made to your measurements, so we can't accept returns.
Is custom worth it for your RV?
Go stock if a standard size fits snugly and you need it this week.
Go custom if:
- No stock size fits your opening
- You want to match an odd or discontinued size
- The vent sits out of the main walkway
- You'd like a color besides white or brown
For more on unusual openings, see our posts on odd-size floor vent replacement and replacing floor vents in an old house. Many of the same problems show up in older mobile homes.
FAQ
What are common RV floor vent sizes? Sizes like 2" × 10" and 2-1/4" × 10" are common and inexpensive off the shelf. Try those first.
Can you make a register for my RV's odd-size opening? If it's up to 6" wide, yes. We make it to your measurements, best at 16" long or less.
How precise do my measurements need to be? Measure to the nearest 1/16", at the opening, not the old cover.
Can I step on it? We don't recommend direct foot load. Place it out of regular foot traffic, or choose metal for walkways.
Does it include a damper? No. Our registers don't include dampers or louvers.
What material should I choose for an RV or camper? PETG. PLA can soften and bend in a hot, closed-up camper, so we don't recommend it for RVs. Request PETG in your order notes or through our contact form.
How much does it cost? Registers start from $35, and the price varies with the cost of the plastic. Ask us about pricing for PETG.
Can I return it if it doesn't fit? No. Every register is custom-made, so we can't accept returns. Measure carefully and send photos if you're unsure.
Get a vent that fits your rig
Tried the stock sizes with no luck? Measure your opening, then order a custom-size floor vent register, starting at $35, and request PETG in your order notes. Not sure yours is a good candidate? Send us a photo and your measurements.
Related:
