We built a deck (2 1/2 years ago) primarily out of "Choice Deck" composite decking (spindles are wood). Last year we noticed black mildew on the floor and pressure washed it w/a soap specifically for pressure washing decks, mildew, etc. This year, it looks real bad, with mildew spots all over the floor decking. we love having composite, but thougt it would fairly maintenence free, aside form regular cleaning. It gets full sun, so never has standing water on it.
What is the best way to clean it AND how can we prevent this from continuing to happen? I’m afraid bleach will ruin the color.
The retailer didn’t talk us into it. We have built wood decks before and chose composite this time because many of our friends and family memebers have had compostie decks for years and love them. None of them have this problem, or we would have reconsidered.
We don’t mind hard work and do maintain our home. That’s why we want it to look nice and CLEAN. I know decks need to be cleaned, we don’t mind doing that. I know that some mildewing is normal, but this mildewing is excessive, so we want to make sure we are cleaning it properly to avoid additional staining.
Honestly, it gets full sun all day from the back…there are no trees near our house.
Maybe we got a bad batch…
To help prevent mold and mildew, sweep the deck regularly to keep
gaps between planks free from debris.
• Keep your gutters clean. Overflow from a leaf-clogged gutter above a
deck is a potential source of food for mold and mildew growth.
• Keep the underdeck area well ventilated and free of materials that
retain moisture.
• Particularly for decks near ground level, a high-quality landscape fabric
should be placed under the deck and covered with washed stone or
pea gravel, to prevent weed growth.
• To help prevent cooking stains, we suggest that grills be placed on a
large mat to reduce the deck’s exposure to staining.
• Plants should be placed in large flower pots or planters and swept beneath
periodically to prevent mold or mildew from soil runoff and trapped moisture.
• When using any deck cleaner, household plastic or rubber gloves
are recommended. Be sure to follow the manufacturer’s instructions
regarding safety, proper use and disposal
General Stains and Cleaning Remedies
All exterior building materials require some degree of maintenance and
cleaning. Composite Decking and Railing is no exception.
Most stains are caused naturally or environmentally and do not constitute
a manufacturing defect. Just like wood, composite decking is not
impervious to grease, mud or stains resulting from normal use and
environmental conditions. The best preventive maintenance for any deck
is to sweep it often. Power-washing is also effective in removing surface
blemishes. Sanding with a very fine grit sandpaper is also effective. For
general cleaning, we have found these products to be effective:
• Olympic® Deck Wash
• Thompson’s® Water SealTM Deck Wash
• Pittsburgh Paints® Ultra Deck Cleaner
If just a portion of the deck is cleaned, there may be a slight difference in
surface appearance between treated and untreated parts of the deck. This
difference will fade over time.
Tannin Stains
Extractive bleeding, also called “tannin staining,” may cause stains on
a deck surface. It frequently happens when objects such as wrought iron
furniture, flowerpots, grills and other items are placed directly on the deck
surface. These stains may also be the result of becoming wet
during storage. Tannin stains occur with decking products made with
wood fibers. contains oak and/or maple, and certain woods,
including oak, contain natural tannins that will “bleed” for a short time
after installation. These stains are temporary and should disappear after
several rain and sun cycles and not reappear. Use the general cleaners
recommended above to remove the stains immediately.
Mold and Mildew
Mold and mildew are part of the environment. They form on virtually any
horizontal surface, and on virtually any material, such as wood, stone,
steel, brass, and composite
decking and railing products.
Mold and mildew will not
damage Composite
Decking and Railing.
Maintaining proper gap
widths, seeing that gaps are
not clogged, and regular
cleaning of the
deck should inhibit the
growth of mold and mildew.
Removing Mold and Mildew
from your Deck
Regular cleaning of Boardwalk Composite Lumber will remove most
mold and mildew growth. The general cleaners recommended below
are effective in removing mold and mildew:
• Olympic® Deck Wash
• Thompson’s® Water Seal Deck Wash
• Pittsburgh Paints® Ultra Deck Cleaner
First, sweep the deck thoroughly, cleaning out any clogged gaps between
planks. Be sure to follow all manufacturer’s instructions regarding safety,
proper use and disposal. For best results, apply cleaner to dry deck with a
broom. Wait 10 to 15 minutes and then rinse with a garden hose or powerwasher
set to low pressure. Should an additional cleaning be necessary, let
the deck dry completely and repeat these steps. The following prepared
solution is also effective:
- 1/3 cup laundry detergent (e.g. Tide®)
- 2/3 cup trisodium phosphate (e.g. TSP or Soilax®)
- 1 quart 5% sodium hypochlorite
(e.g. Clorox® or other liquid chlorine laundry bleach)
- 3 quarts water
Use of household plastic or rubber gloves with any deck cleaner is
recommended. As with other commercial cleaners, be sure to take
precautions to protect plants, surroundings, clothing and exposed skin.
CAUTION: Greater concentration may cause discoloration. Do not mix
other cleaners with the deck wash solution Good Luck !
Composite decking is a waste of time and money,and is not impervious to mold,stains etc as your retailer would like for you to believe and probably told you it was in order to get you to spend all that extra hard earned money to buy it.
Contact the manufacturer for assistance,home improvement centers care about one thing only,sales,so screw you afterwards.
And next time you are considering buying a "lifetime" material for home improvements,remember this,90% of American homeowners only spend 9 years in their homes before they sell.
References :
28 years residential construction.
Your deck must be shaded.
Mix a solution of 50% bleach and 50% water in a garden sprayer. Wet the deck thourghly, let stand 30 minutes and wash off with a high pressure hose nozzle.
The bleach will delay but not totally prevent reoccurance of the mildew.
References :
To help prevent mold and mildew, sweep the deck regularly to keep
gaps between planks free from debris.
• Keep your gutters clean. Overflow from a leaf-clogged gutter above a
deck is a potential source of food for mold and mildew growth.
• Keep the underdeck area well ventilated and free of materials that
retain moisture.
• Particularly for decks near ground level, a high-quality landscape fabric
should be placed under the deck and covered with washed stone or
pea gravel, to prevent weed growth.
• To help prevent cooking stains, we suggest that grills be placed on a
large mat to reduce the deck’s exposure to staining.
• Plants should be placed in large flower pots or planters and swept beneath
periodically to prevent mold or mildew from soil runoff and trapped moisture.
• When using any deck cleaner, household plastic or rubber gloves
are recommended. Be sure to follow the manufacturer’s instructions
regarding safety, proper use and disposal
General Stains and Cleaning Remedies
All exterior building materials require some degree of maintenance and
cleaning. Composite Decking and Railing is no exception.
Most stains are caused naturally or environmentally and do not constitute
a manufacturing defect. Just like wood, composite decking is not
impervious to grease, mud or stains resulting from normal use and
environmental conditions. The best preventive maintenance for any deck
is to sweep it often. Power-washing is also effective in removing surface
blemishes. Sanding with a very fine grit sandpaper is also effective. For
general cleaning, we have found these products to be effective:
• Olympic® Deck Wash
• Thompson’s® Water SealTM Deck Wash
• Pittsburgh Paints® Ultra Deck Cleaner
If just a portion of the deck is cleaned, there may be a slight difference in
surface appearance between treated and untreated parts of the deck. This
difference will fade over time.
Tannin Stains
Extractive bleeding, also called “tannin staining,” may cause stains on
a deck surface. It frequently happens when objects such as wrought iron
furniture, flowerpots, grills and other items are placed directly on the deck
surface. These stains may also be the result of becoming wet
during storage. Tannin stains occur with decking products made with
wood fibers. contains oak and/or maple, and certain woods,
including oak, contain natural tannins that will “bleed” for a short time
after installation. These stains are temporary and should disappear after
several rain and sun cycles and not reappear. Use the general cleaners
recommended above to remove the stains immediately.
Mold and Mildew
Mold and mildew are part of the environment. They form on virtually any
horizontal surface, and on virtually any material, such as wood, stone,
steel, brass, and composite
decking and railing products.
Mold and mildew will not
damage Composite
Decking and Railing.
Maintaining proper gap
widths, seeing that gaps are
not clogged, and regular
cleaning of the
deck should inhibit the
growth of mold and mildew.
Removing Mold and Mildew
from your Deck
Regular cleaning of Boardwalk Composite Lumber will remove most
mold and mildew growth. The general cleaners recommended below
are effective in removing mold and mildew:
• Olympic® Deck Wash
• Thompson’s® Water Seal Deck Wash
• Pittsburgh Paints® Ultra Deck Cleaner
First, sweep the deck thoroughly, cleaning out any clogged gaps between
planks. Be sure to follow all manufacturer’s instructions regarding safety,
proper use and disposal. For best results, apply cleaner to dry deck with a
broom. Wait 10 to 15 minutes and then rinse with a garden hose or powerwasher
set to low pressure. Should an additional cleaning be necessary, let
the deck dry completely and repeat these steps. The following prepared
solution is also effective:
- 1/3 cup laundry detergent (e.g. Tide®)
- 2/3 cup trisodium phosphate (e.g. TSP or Soilax®)
- 1 quart 5% sodium hypochlorite
(e.g. Clorox® or other liquid chlorine laundry bleach)
- 3 quarts water
Use of household plastic or rubber gloves with any deck cleaner is
recommended. As with other commercial cleaners, be sure to take
precautions to protect plants, surroundings, clothing and exposed skin.
CAUTION: Greater concentration may cause discoloration. Do not mix
other cleaners with the deck wash solution Good Luck !
References :
Source: Spouse of Construction business Owner thirty years in business
Bleach
References :