Power washing is a popular and effective way to clean outdoor surfaces like composite decking. However, there has been some debate around whether the high-pressure water can damage Trex and other composite deck boards. Here is a look at the key considerations when power washing Trex decking.
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Can You Power Wash Trex Decking?
According to Trex, their composite decking products are safe to clean with a pressure washer. Trex states that their decking is resistant to staining, fading, and scratching, and can thus withstand the pressure from power washing. They recommend using a fan tip nozzle and keeping the pressure under 3100 PSI when cleaning Trex decking.
Most composite decking manufacturers state their products can be power washed, though specific pressure and nozzle recommendations may vary. In general, power washing composite decks is considered safe if done properly.
Risks of Power Washing Trex Decks
While Trex and other composite decks are designed to stand up to power washing, there are some risks to be aware of:
- High pressure could damage the deck surface if too much pressure is used or the nozzle is held too close
- Debris stuck in the nozzle could scratch the decking
- Power washing can push dirty water into deck board seams, staining the substructure
- Over-saturation from excessive power washing can lead to structural damage
Setting the pressure washer too high or not using the right technique increases the risk of surface damage or water damage to the Trex deck.
Proper Technique for Power Washing Trex
When power washing Trex or other composite decks, follow these tips:
- Use a wide-fan nozzle, 25 degrees or greater
- Keep nozzle 6-8 inches above the deck surface
- Use pressures under 3100 PSI
- Work in the direction of the wood grain
- Rinse at a 90 degree angle to prevent pushing debris into seams
- Avoid holding nozzle over one spot too long
- Allow deck to fully dry before sealing, staining or using
Proper power washing technique will help avoid any surface damage or excess water saturation.
Cleaning Products for Trex Decks
In most cases, power washing with water is sufficient for cleaning Trex decks. If more extensive cleaning is needed, here are some cleaning products that can be safely used:
| Cleaner | Notes |
|---|---|
| Trex Deck Cleaner | Specialized composite deck cleaner by Trex |
| Dish soap and water | Use mild dish detergent mixed with water |
| White vinegar | Helps remove stuck-on debris and grease |
| Baking soda | Makes a gentle abrasive cleaner when mixed with water |
| Oxygen bleach cleaner | Removes mold, mildew, and other stains |
Avoid harsh chemicals, strong solvents, or abrasive cleaners. Always test cleaners on a small inconspicuous area first before applying to the full deck.
When to Avoid Power Washing Trex
There are some situations when power washing is not recommended for Trex decks:
- Hot surfaces – Power washing when deck is hot can cause damage
- Newly installed deck – Allow at least 2-3 months before power washing new Trex decking
- Extremely dirty surface – May require chemical cleaner before power washing
- Visible scratches or damage – Power washing will make damage worse
Avoid power washing when the deck is excessively hot from sunlight, as this can lead to cracking or warping. Let newly installed decks weather and settle before exposing them to power washing.
Signs of Damage from Power Washing
How can you tell if power washing has damaged the deck? Here are signs to watch out for:
- Visible scratches, gouges or furrows
- Roughened texture – should feel smooth
- Fading or discoloration in spots
- Warping or deformation of boards
- Splitting at board ends
Excessive pressure or holding the nozzle too close can damage the deck surface. Immediately stop power washing if any scratches, marks, or other damage becomes visible.
Related Questions
Does Trex fade?
Trex decking is designed to resist fading. The company offers a fade and stain warranty for their products. However, some gradual fading over time is normal, especially on horizontal surfaces that get full sun exposure. Fading can be minimized by periodic cleaning and Trex protective sealers.
What PSI should I use to power wash composite decking?
Most composite decking manufacturers recommend keeping pressure under 2000-3100 PSI when power washing. Using fan tip nozzles and keeping the nozzle 6-8 inches above the deck prevents damage from excessive pressure on any one spot.
How often should Trex decking be power washed?
Trex recommends cleaning their decks at least twice per year with soap/water or power washing. More frequent washing may be needed for decks in wooded areas or under trees. Excess pollen, debris and dirt buildup should be removed before it becomes difficult to clean.
Conclusion
Power washing is an effective way to clean Trex and other composite decks. However, care should be taken to use proper pressure and technique to avoid surface damage. Always follow the manufacturer’s recommendations, test a small area first, allow newly installed decks time to settle before washing, and immediately stop if any damage becomes visible.
With the right precautions, power washing is generally safe for Trex and can help keep your deck looking like new. Proper cleaning is important for maintaining the appearance and performance of composite decking.