RV Awning Adjustment: Setting Arms, Pitch, Fabric Tension and Alignment
Quick answer
Most RV awning adjustments are made at the arms: main arm height sets pitch, rafter or slide arms set fabric tension, and equal settings on both sides keep the roller tube square so fabric rolls straight. Lower one end several inches for rain, keep the fabric taut but not drum-tight, and leave roller tube spring re-tensioning to the manufacturer's procedure or a technician because the stored energy can cause serious injury.
Adjusting an RV awning mostly means setting the arms correctly. On a manual vertical-arm patio awning, the main arms control height and pitch, the rafter (slide) arms push the roller tube outward to tension the fabric, and matching settings on both sides keep the roller tube parallel to the coach so the fabric rolls up straight. Lateral-arm power awnings have fewer adjustments, usually just pitch at the arm shoulders on some models. The one adjustment that is not routine is roller tube spring tension: it is a periodic, hazardous job that should follow the manufacturer's procedure exactly.
This guide covers the adjustments owners commonly make and the symptoms that call for each. For awnings that are stuck out, see RV awning won't retract, and for wind and rain habits, see RV awning care and wind safety.
Know which adjustments your awning has
| Adjustment | Manual vertical-arm | Power vertical-arm | Power lateral-arm |
|---|---|---|---|
| Pitch (front height) | Yes, main arm inner tube locks at several heights | Limited on many models | On some models, at arm shoulder or bracket |
| Rain dump (one end lower) | Yes, set one main arm lower | Varies | Rarely; often none |
| Fabric tension | Rafter arm slide and knob, plus roller spring | Mostly set by spring and motor | Set by arm springs; not owner-adjustable |
| Patio (legs to ground) position | Yes on many | Some | No |
| Roller tube spring | Yes, hazardous | Some designs have one | Usually none |
If you are unsure what you have, the RV awnings guide explains the designs, and awning parts names each component.
How the arms work
A manual vertical-arm patio awning has two arm assemblies, one at each end. The main arm runs from a bottom bracket low on the sidewall up to the end of the roller tube. Its inner tube telescopes and locks at set positions, which controls how high the front of the awning sits. The rafter arm (also called the slide or upper arm) runs from near the awning rail to the main arm or roller end, and its sliding section, locked by a knob or lever, pushes the roller tube away from the coach. That push is what pulls the fabric taut against the spring in the roller tube.
Because each side is set independently, most alignment problems come from one side being set differently from the other.
Setting pitch for sun and rain
RV awnings cannot match the drainage pitch of a residential awning, which commonly aims for about 14 degrees, or roughly 3 inches of drop per foot of projection (see awning projection and pitch). That would put the front of an 8 ft RV awning about 2 ft lower than the rail, low enough to block the door and hit heads. Instead, RV owners combine moderate front-to-back pitch with a rain dump: one end set lower than the other so water runs to a corner.
Worked example
An 18 ft awning with 8 ft (96 inches) of projection has its front set 10 inches lower than the rail. Front-to-back slope is 10 / 96 = 0.104, about 6 degrees. Lowering one main arm so that end is another 8 inches lower adds a side-to-side slope of 8 / 216 = 0.037, about 2 degrees. Water now runs diagonally toward the low corner. The steepest fall combines both: the square root of (0.104 squared + 0.037 squared) = 0.110, about 6.3 degrees, still far below 14 degrees, which is why RV fabric pockets easily if the dump end is not low enough. Check after the first heavy shower: if water pools, lower the dump end further.
- Set both main arms to the same height first, with the front of the awning comfortably above head height at the door.
- Choose the dump end, away from the entry door, hookups and the picnic table.
- Lower that main arm one or more positions until the end is noticeably lower, often by at least 6 to 12 inches on a full-length patio awning.
- Re-tension the rafter arms after changing heights, because lowering one end changes fabric tension on that side.
- Confirm the locks are fully seated on every arm. A partly engaged lock can let an arm collapse under a water load.
Fabric tension: rafter arms and spring
Correct tension is taut enough that the fabric does not sag, flap or pocket, but not so tight that it strains the stitching or makes the rafter arms hard to lock. A simple check is to press the middle of the fabric with a flat hand: it should give a little and spring back, with no visible sag between the arms.
- Rafter arm adjustment is the everyday tension setting. Loosen the knob, slide the arm out to push the roller tube away from the coach until the fabric is taut, then tighten. Do both sides equally.
- Roller spring tension sets how firmly the awning rolls up and how much pull the fabric has when out. It weakens with age and can be lost when fabric is replaced without counting turns. Symptoms of low spring tension include fabric that will not tighten even with rafter arms fully out, slow or loose roll-up, and an awning that creeps open. Excess tension makes the awning hard to pull out and snaps it up violently.
Spring safety: the roller tube spring on a manual RV awning stores enough energy to spin the tube and seriously injure hands and wrists. Adding or removing spring turns requires locking the tube, holding the end cap under load and following the manufacturer's exact sequence and turn count for your awning length. If you do not have that procedure, a helper and the right tools, have an RV technician do it. The process is also part of fabric replacement, described in RV awning fabric replacement.
Squaring the roller tube and fixing fabric drift
When the roller tube is not parallel to the awning rail, the fabric is tighter on one side and tends to walk toward one end as it rolls up, a problem called telescoping. Over time this causes wrinkles, a fabric edge rubbing the arm, and a roll that jams.
- Extend fully and set both rafter arms the same way.
- Measure from the awning rail to the roller tube at each end, straight out from the coach. The two figures should match within about half an inch.
- Adjust the short side by sliding its rafter arm out (or the long side in) until they match, then lock both.
- Check fabric overhang at each end of the roller tube. It should be roughly equal. If the fabric itself is off-center on the tube, it was installed that way, and re-centering may require sliding the fabric in the rail, a job that usually involves releasing spring tension.
- Roll up slowly and watch the fabric edges. If it still drifts, check for a bent arm by comparing both sides' angles and lengths, and for a stretched or damaged fabric panel.
Lateral-arm power awnings track by the same principle, but the arms are not owner-adjustable. Persistent drift on those usually means a bent arm or bracket that has shifted; see awning retracts unevenly and awning arm replacement.
Travel position and hardware checks
An awning that does not sit tight against the coach in travel position rattles, wears and can catch wind on the road. Common adjustments and checks:
- Main arms fully collapsed and seated in their top and bottom travel locks.
- Rafter arms fully retracted and stowed alongside the main arms.
- Roller tube direction lever (manual) set to the travel or locked position.
- Bracket screws at the top and bottom of each arm tight, with sealant intact behind them. Loose bracket screws in the sidewall let water in and let the arm move.
- No fabric loop hanging below the roll, which indicates low spring tension or a fabric problem.
- Pivot rivets and pins without excess play. Sloppy pivots throw off pitch and tension settings.
Which symptom calls for which adjustment
| Symptom | Adjust or check |
|---|---|
| Water pools in the middle | Lower one main arm for a rain dump; re-tension rafter arms |
| Fabric sags or flaps with arms set correctly | Rafter arm extension; then roller spring tension (technician) |
| Fabric walks to one end when rolling | Square the roller tube; check for bent arm |
| Awning hard to pull out, snaps back hard | Spring over-tensioned (technician) |
| Awning creeps open in travel | Travel locks, direction lever, low spring tension |
| Arm collapses under light load | Arm lock not seated or worn; replace lock hardware |
| Awning rattles on the road | Travel locks and bracket screws |
DIY or technician
Owner jobs: pitch and rain dump settings, rafter arm tension, squaring the roller tube, tightening accessible bracket screws and checking locks. Technician jobs: roller spring re-tensioning, fabric re-centering, bent arm replacement and anything on a power awning's motor end. Disconnect 12V power before working near the motor of a power awning. If an adjustment does not hold, the parts may be worn rather than misadjusted, and an older awning with worn arms, tired spring and aging fabric may be a candidate for replacement; compare costs in power vs manual RV awnings.
Frequently asked questions
How do I adjust the pitch on my RV awning?
On a manual vertical-arm awning, unlock the inner tube of each main arm and set it to a lower or higher position, then re-lock and re-tension the rafter arms. For rain, set one end several inches lower than the other so water runs to a corner. Many lateral-arm power awnings have limited or no pitch adjustment, so check your manual.
How tight should RV awning fabric be?
Taut enough that it does not sag, flap or form pockets, but not drum-tight. Pressing the middle with a flat hand should give a little and spring back. Set tension mainly with the rafter arms, adjusting both sides equally. If the fabric stays loose with the rafter arms fully extended, the roller tube spring has likely lost tension.
Why does my RV awning fabric roll up crooked?
Usually because the roller tube is not parallel to the coach, so one side of the fabric is tighter than the other. Measure from the rail to the roller tube at both ends and adjust the rafter arms until they match. If it still drifts, check for a bent arm, off-center fabric on the roller, or a stretched panel.
Can I tighten the spring on my RV awning myself?
It is possible but risky. The roller spring stores enough energy to cause serious injuries if the end cap slips. Only attempt it with the manufacturer's procedure and turn count for your awning length, the correct tools, a helper, and the roller tube locked. Many owners leave spring work to an RV technician.
How much lower should one end be for a rain dump?
Enough that water visibly runs to the low corner instead of collecting in the middle; on a full-length patio awning that is often at least 6 to 12 inches lower than the other end. Fabric stretches when wet, so check after the first heavy shower and lower the dump end further if a pocket begins to form.
Sources and further reading
- Dometic: manual patio awning installation and operating instructions
- Carefree of Colorado: patio awning owner's manuals and adjustment guides
- Lippert: Solera awning installation and owner's manuals
- RV Industry Association (RVIA): RV owner education resources
How we write our guides: figures are typical US ranges checked against manufacturer documentation, published standards and installer pricing. Read our editorial standards. Spotted an error or outdated detail? Request a correction.