How To Install Landscape Timbers Retaining Wall

A timber retaining wall is a toll effective option for flattening out your belongings. As we learned in this post, all wood in a timber retaining wall must be pressure treated to UC4A or UC4B standards (UC4B preferred). The timbers shall be 6″x6″ or 8″x8″. To further help with wood protection, nosotros will ensure the wood does non contact natural ground and the wall has proper drainage.

Tools

Hand Tamper
Shovel
Gloves
Wheel Barrow
4-ft Level
Torpedo Level
Sledgehammer
Drill (if using screws)
Round Saw or Chainsaw

Cross Department of two-ft tall timber retaining wall

Foundation

Dig a trench that is at least 12-inches wide. For walls between 0-2 ft, dig an 8-inch minimum depth. Compact the bottom of the trench using a hand tamper. Cheque out more than information on preparing the foundation hither.

After compacting the foundation, identify the base material. The base of operations material must consist of at least 4-inches of clean crushed stone such as No. 57 stone. The make clean crushed rock will remove water from under the wall helping to forbid h2o damage to the timbers. For more information on retaining wall backfill materials, check out this post.

Meaty the base fabric using the hand tamper.

Setting Starting time Row of Timbers

rebar in first row of timber retaining wall — Driving rebar through first row of timbers.

Identify the outset row of timbers directly on the crushed rock base. Start at a corner or construction that you are abutting against. Leave no gap between the timbers. Then, ensure the timbers are completely level along the length of the timber by using a 4-ft level. Utilise a torpedo level to level the timber from front to back. Utilize a deadblow or small sledge hammer to arrange the timbers.

Drill two holes at 4-ft autonomously on each timber on the lesser row. The holes should be the same diameter as the rebar. The length of the rebar should exist at least two-ft. Drive the rebar through the holes with a sledge hammer.

Subsequent Rows of Timbers

Stagger the joints of the next row of timbers from the ones below. This helps the stability of the retaining wall. Aim to identify at least a quarter of the length of the timber by a joint (for viii-ft timbers, this is at least ii-ft). Also, ready each row of timbers with a 1/2-inch setback from the one beneath. This dramatically helps with the stability of the wall.

Setback on timber retaining wall — Each timber is setback by 1/2-inch from the one beneath for stability. In add-on, each joint is start from the one above and below.

Leaning timber retaining wall — This timber retaining wall has a slight visual lean considering it was not built with a setback or batter.

Note: Many retaining walls are congenital without offsetting each row. These walls also lean out and fail over fourth dimension. Vertical woods walls besides await like they are leaning out, even if they are built straight. If there is no convincing you of edifice your retaining wall with a 1/ii-inch offset, then batter the timbers toward the backfill side by 5-degrees. This will help the retaining wall expect vertical after completing the wall. To accomplish this, tape half dozen quarters on ane finish of your torpedo level. Identify the side with quarters near the fill side of the timber when leveling from front to back.

Attach each row of timbers to the one below using iii/8″x12″ galvanized nails*, 12″ stainless steel screws*, or 12″ ACQ approved coated spiral*. Because the copper in the pressure level treatment is corrosive, use hot-dipped galvanized or stainless steel nails/screws. Practise not utilize electroplated (or zinc plated), uncoated, painted, or other type of coating unless information technology is rated for ACQ force per unit area handling. These alternative coatings are fine for an above footing deck, but they do non provide the necessary corrosion protection needed for pressure treated wood that is in contact with the ground. Space the nails or screws every 2-ft along the timber.

Installing Drainage

H2o cannot easily period through woods similar it can through porous segmental blocks. This means you demand special accommodations to ensure water does not build up behind the wall. Place a minimum of 12-inches of drainage stone (a clean crushed rock such as No. 57 rock) behind the timbers. This, combined with the clean crushed stone used for the base, will help the water drain underneath the wall.

Run a 3-in or 4-in perforated pipage behind the wall and outlet every 30 to forty ft. Plan an outlet for the pipe the lowest points on the wall. The everyman bespeak may either be at the cease of the wall or somewhere in the middle. An outlet in the middle will require a hole in the timbers.

Compact the drainage stone with a hand tamper. Continue placing the drainage stone to within 4-inches of the of the wall. When y'all become to the top of the wall, place filter material above the drainage stone. Extend the fabric upward the back of the timbers and attach with construction adhesive. Extend the filter textile at least half-dozen-inches past the drainage stone.

Cut Wood

Timbers are too thick to cut with a standard circular saw in one cut. To employ a circular saw, you will need to cut one border, rotate the timber, cut again, and go along this until you accept complete sawn through the timber. Alternatively, use a chainsaw to Wear a mask to avoid breathing in whatever dust from cutting pressure level treated wood.

coper wood preservative for pressure treated wood — Applying copper based wood preservative

Pressure handling but extends an inch or so into the wood. So, when y'all cut through the forest or drill a hole, the cut border will exist untreated. Treat whatsoever cut edge with a paintable copper based woods preservative*. Use a foam paint castor* to use the preservative.

Concluding Thoughts

A timber retaining wall tin be a neat feature for your backyard projection. The steps for edifice a wall up to 2-ft tall are simple. Apply UC4B force per unit area treated wood, install clean crushed amass on all surfaces that bear upon the wood, pin the bottom row of timbers, and coat all cutting edges. In the next post, we will go over timber walls greater 2-ft and how to install deadman anchors.

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