LandscapeArchitectureQuality landscape architecture demandsmaterials that are beautiful and long lasting. Wood used outdoors must with-stand environmental elements, yet retainits symmetry and aesthetic purpose.

Redwood is the one wood that meetsthese landscaping requirements.

Redwood Decksare Outdoor RoomsRedwood decks are living rooms. Break-fast rooms. Exercise rooms. Rooms forsunbathing. Rooms for gatherings offriends and family. Rooms for quiet timeswith a good book.

Outdoor rooms are different from ordinaryrooms. They serve as an intermezzobetween home and nature. The air is fresh. You can feel the sun’s warmth andsmell the garden. Nature air-conditions outdoor rooms with soft breezes, and outdoor rooms are the perfect place towatch shadows grow and the stars comeout on a summer night.

Quality landscape architecture requiresbuilding materials that are beautiful andlong lasting. Materials need to with-stand environmental elements yet retaintheir symmetry and aesthetic purpose.Redwood has a well-earned reputationfor meeting these requirements. Equallyimportant, there are cost-effective redwood grades to specify for every project, whether it is a public plaza or a residential garden.

Performance is more than durability.Redwood has qualities not found in otherwoods—even woods treated with chemi-cals. Redwood performance charac-teristics include resistance to shrinking,warping and checking in addition to durability. This means redwood pro-jects age beautifully. Decks, fences andshelters made with redwood simply look better ten, fifteen and twenty years after construction.

Total Performance Dimensional Stability According toreports from the Forest Products Labora-tory of the U.S. Department of Agriculture,redwood has less volumetric and tangen-tial shrinkage than other common domes-tic softwoods. In exterior use, this meansredwood stays flat and straight with minimal warping, cupping or checking.

Resistance to Decay and InsectsRedwood heartwood has grown-in resist-ance to decay and insects that is presentthroughout the lumber, not just on thesurface. The wood exposed through saw-ing, boring or nailing is as decay-resistantas the surface.

Finish Retention Redwood has an open celled structure and contains little orno pitch or resin. This enables redwoodto absorb and retain all types of finishesextremely well.

Treating lumber with chemicals increasesits decay resistance but doesn’t improveother characteristics of the species. Inmany applications, other aspects of woodperformance take precedence. For exam-ple, wood off the ground but exposed to harsh sunlight needs resistance tochecking and warping. Beauty is usuallythe primary concern in highly visible applications such as decking surfaces,fences and overhead shelters. In mostsituations the wood’s workability, finishretention or the absence of pitch andresin is important.

Performance Characteristicsof Construction Woods

California redwood 26 3 3 3 3 3 2 3 2 2 2

Douglas fir-larch 23 2 2 2 1 2 2 2 3 3 3

Western cedar 22 3 3 3 3 3 1 3 1 1 1

Southern pine 22 2 2 2 1 1 3 2 3 3 3

Eastern hemlock 21 3 2 1 2 3 2 2 2 2 2

Hem-fir 19 2 2 1 1 3 2 2 2 2 2

Idaho white pine 19 2 3 1 3 3 1 3 1 1 1

Spruce-pine-fir (Canada) 17 2 2 1 1 3 2 1 2 2 1

Englemann spruce-lodgepole pine 15 2 2 1 1 3 1 3 1 1 1

3 Among woods relatively high in the characteristic listed.

2 Among the woods intermediate in the respect.

1 Among the woods relatively low in that respect.

Rankings of species taken from:How to Buy Construction Lumber University of Wisconsin-Extension/Madison, September 1979

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Redwood Lumber GradesRedwood grades are established in theStandard Specifications for Grades of California Redwood Lumber issued by theRedwood Inspection Service. Properlygrademarked lumber will bear the RIS mark or that of another accreditedinspection bureau.

Garden Grades These economicalgrades of redwood are tailor-made foroutdoor applications. Their varied woodgrains and knot-textured surfaces blendwell with other natural materials. Gardengrades are available dry or unseasonedand are usually surfaced on four sides(S4S). They are available in dimensionsfrom timbers 20 feet in length to benderboard, used for edging garden walkways.

Construction Heart/Deck HeartAll-heartwood grades containing knots;recommended for work on or near theground such as posts, beams, joists anddecking. Deck Heart has similar appear-ance and uses as Construction Heart butis also graded for strength. Deck Heart isavailable in 2x4 and 2x6 only.

Construction Common/Deck CommonContain knots and combination of heart-wood and sapwood; recommended forabove-ground applications such as rail-ings, fence boards, benches and decking.Deck Common has similar appearanceand uses as Construction Common but isalso graded for strength. Deck Commonis available in 2x4 and 2x6 only.

Merchantable Heart Most economical all heartwood grade, allowing larger knotsand some knotholes; used for retainingwalls and garden or utility structures on ornear the ground.

Merchantable Same characteristics as Merchantable Heart but containingsapwood; suitable for fence boards, trellises and above-ground garden andutility applications.

Architectural Grades Architecturalgrades of redwood should be specifiedwhere the visibility and design integritycall for the material to maintain its appear-ance long beyond initial application. Thesequality redwood grades are availableCertified Kiln Dried, S-Dry or unseasoned.Unequaled in beauty and stability, theyare the best choice for precision joineryand intricate or formal architectural designs.

Clear All Heart AII heartwood, free of knots; recommended for highly visible applications.

Clear Similar quality to Clear All Heartexcept containing sapwood; ideal forhighly visible, above-ground applications.

B Heart Contains limited knots and char-acteristics not permitted in clear grades;uses similar to Clear All Heart.

B Grade Similar characteristics as BHeart but containing sapwood; same usesas Clear.

Garden Grades Architectural Grades

■ Suitable grade for useMost economical grade for use

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Architectural ——— ——— ——— ——— ■ ■ ■ ■

Garden ■ ■ ■ ■ ——— ——— ——— ———

Knots ■ ■ ■ ■ ——— ——— ■ ■

Sapwood ——— ■ ——— ■ ——— ■ ——— ■

Posts ■ ——— ——— ——— ■ ——— ■ ———

Beams ■ ——— ——— ——— ■ ——— ■ ———

Joists ■ ——— ——— ——— ■ ——— ■ ———

Decking ■ ■ ——— ——— ■ ■ ■ ■

Rails ■ ■ ——— ——— ■ ■ ■ ■

Fenceboards ■ ■ ■ ■ ■ ■ ■ ■

Benches ■ ■ ■ ■ ■ ■ ■ ■

Planters ■ ——— ■ ——— ■ ——— ■ ———

Trellises ■ ■ ■ ■ ■ ■ ■ ■

Furniture ■ ■ ■ ■ ■ ■ ■ ■

Sizes of Garden Grade LumberUnseasoned Lumber, Nominal and Actual

Thickness WidthNominal Actual Nominal Actual

S2S S2E

3⁄4 11⁄16 2 19⁄16

1 25⁄32 3 29⁄16

11⁄4 11⁄32 4 39⁄16

11⁄2 19⁄32 5 49⁄16

2 19⁄16 6 59⁄16

21⁄2 21⁄16 8 73⁄83 29⁄16 10 93⁄84 39⁄16 12 113⁄85 41⁄2 Over 12 Off 5⁄86 51⁄2Over 6 Off 1⁄2

GrainLumber has either flat or vertical grain.Orders for Clear All Heart and Clear may specify a grain. Garden grades areshipped as mixed grain but can be field-selected for desired use. When used fordeck surfaces, flat grain redwood shouldbe applied with the bark side up for bestperformance. Vertical grain lumber willprovide the smoothest surface for railingsand benches.

Vertical Grain Flat Grain

TextureRedwood is generally available surfaced(S4S) or rough. Surfaced lumber is bestfor decking or areas that are to be painted.

SeasoningUnseasoned redwood is suitable formost landscaping applications, but air-seasoned or kiln dried redwood oftenhas a better appearance and providesenhanced stability and finish retention.Dry lumber is lightweight making it easyto work with.

Specifying RedwoodTo ensure delivery of the right lumber forthe purpose intended, the specificationshould include: use, grade, grain,seasoning, size and texture.

For exampleRedwood lumber for (use) decking shallbear the Redwood Inspection Servicegrade mark and shall be (grade)Construction Common, (seasoning)unseasoned, (size) 2x6, (texture) S4S.

Redwood specifications should alwaysrequire the use of top-quality corrosionresistant fasteners.

Annual Rings Bark Side Pith Side

Redwood Decks

Redwood decks create a natural focalpoint for outdoor living environments. Aswalking surfaces and entertaining areas,decks organize large spaces and reclaimirregular or sloped land. Redwood stairsand walkways provide attractive footpaths.

Redwood decks range from simple platforms to multi-level projects using a variety of shapes and amenities. Openingsin the deck surface can allow for plantingsand incorporate elements of outdoor furniture. Decking may be parallel ordiagonal. Redwood’s superior stabilityalso permits the use of parquet patterns.

Concrete footings provide the best sup-port for deck framing. Tops of footingsshould extend 6 inches above ground andshould be pitched outward to prevent watercollection and inhibit decay and insects.

Deck framing tables shown on this pageare for single spans of non-stress gradedConstruction Heart and ConstructionCommon redwood. Design will support auniform live load of 40 pounds/squarefoot with deflection limited to L/240.

Concentrated loads of planters, spas andother heavy objects may require additionaljoists and larger beams. Local buildingcodes should be consulted regardingstructural regulations.

Design loading, with deflection limited toL/180, sets a maximum 24-inch span for2-inch-thick decking and 16-inch span for5/4-inch-thick decking. Provide 1/8 inchminimum space between boards, andcenter all large knots and butt-jointedboard ends over joists.

Beam span is the distance a beamextends from one post to the next. Beamspacing is the distance between beams.Deflection is limited to L/240.

Suggested Beam Spans

Beam BeamSpacing Sizes

4x6 4x8 4x10

Span Span Span6 feet 4'0'' 5'0'' 7'3''8 feet 3'3'' 4'3'' 6’3''10 feet 3'0'' 3'9'' 5'6''12 feet 2'9'' 3'6'' 5'0''

Suggested Joist Spans

Joist Joist JoistSize Spacing Span

2x6 16'' on center 7'3''24'' on center 6'0''

2x8 16'' on center 10'9''24'' on center 8'9''

2x10 16'' on center 13'6''24'' on center 11'0''

Redwood Shelters

Overhead structures of redwood give thefinishing touch of shelter to comprehen-sive landscaping, creating shade andspatial definition. Post-and-beam framessupport pitched or horizontal rafters,spaced for varying degrees of shade orto hold finer scale screening. Canvas orplastic coverings provide rain protection.In some situations permanent roofing isappropriate. Vertical trellis panels offerprotection from sun and wind.

Redwood Plantersand Seating

Because redwood is naturally stable, it isideal for planters, seating and tables. Theseelements can be movable or built-in.

Planters use Construction Heart or otherall-heartwood grades of redwood wherethere is soil contact. Large planters, withmore than 1 foot of soil depth, may require2-inch boards.

Seating is often as simple as providing2x8 or 2x10 caps at low walls or planters.Platform or backed benches may be freestanding or components of other elements. Install seatboards bark side upto reduce grain raising and splintering.

Redwood Fences

Redwood garden grades create a pleas-ant fencing with excellent stability anddurability. Fences of various heights andin many patterns can be designed toscreen, protect, divide, decorate, shelterand shade.

Whether they are distinctive or subtlyblended into an overall design, mostfences serve many purposes. The “goodneighbor” fence with its finished appear-ance on both sides, enhances the valueof two properties. “Attractive nuisance”fences, such as those required aroundswimming pools, provide barriers. Retain-ing walls, shelters, planters and benchescan be integrated with fence construction.

Finishes

Redwood weathers more gracefully thanmost woods. Exterior finishes such aswater repellents, semitransparent stainsand weathering stains enhance redwood’snatural beauty and performance. Testsconducted by the Forest Products Labo-ratory of the U.S. Department of Agricul-ture have shown that no other domesticwood accepts and retains finishes betterthan redwood.

Always follow finish manufacturer’s recommendations regarding applicationconditions, coverage and number ofcoats required. Brushing is the bestmethod for applying finishes, followed byroller applications and spray applications.Finishes which contain water repellentsand mildewcides will provide the greatestdegree of protection. Linseed oil, if usedalone, tends to attract dirt and mildew,resulting in discoloration.

Penetrating finishes should be applied toclean dry surfaces as soon as possibleafter construction is completed. Pre-finishing is advantageous in that all surfaces of the lumber can be treated.

Oil-based solid-color stains and paintsshould be applied to unseasoned redwood only after the wood has becomesufficiently dry. This may take from one tosix months. If coatings must be applied to unseasoned wood before this time,water-borne products should be used

over a stain-blocking latex primer formu-lated for redwood.

Finally, don’t use clear film-forming var-nishes, lacquers or “shake and shingle”type paints on exterior redwood.

Redwood Finishes

Uses

Decks/Walkways ■ ■ ■ ■ ——— ———

Fences ■ ■ ■ ■ ——— ———

Planters/Retaining Walls ■ ■ ■ ■ ——— ———

Seating ■ ■ ■ ■ ——— ———

Tables ■ ■ ■ ■ ■ ———

Garden Shelters ■ ■ ■ ■ ■ ———

Effect

Color Natural Driftwood Selected Selected Selected ———

Grain Visibility High Medium Medium None None ———

Application

Recommended Coats* 2 1-2 2 2 2 ———

Primer Required None None None None Oil/Alkyd ———

Refinish—Years 1-2 ——— 2-5 2-5 5-10 ———

Non-toxic formulations Traffic bearing formulations Certified Kiln Dried lumber only*Follow manufacturer’s recommendations.

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Fasteners

All nails, fasteners and hardware mustbe stainless steel, aluminum or top-quality,hot-dipped galvanized (electroplated galvanizing is not acceptable). Poor quality fasteners will react with redwood’snatural, decay-resisting extractives causing unsightly stains.

A staggered nailing pattern helps to avoidsplitting of redwood garden grade lumberby allowing slight movement during thewood’s natural seasoning process.

Storage

Redwood lumber should be stacked flat,supported 6 inches off the ground andprotected with a waterproof cover thatpermits air circulation. If stored more thana month, unseasoned lumber should bestored with stickers between boards topermit excess moisture to evaporate.

Additional LiteratureDeck ConstructionDecks, Grades, Nails, FinishesRedwood Grades and UsesExterior Finishes

PlansRedwood Fences For All ReasonsRedwood Design-A-Deck™ Plans KitDeck Around TubDeck Over Concrete8x10 DeckShade Shelter

CaliforniaRedwood Association405 Enfrente Drive, Suite 200Novato, CA 94949-7206Telephone 415-382-0662Toll Free 888 Cal-RedwoodFax 415-382-8531www.calredwood.org Redwood—our renewable resource

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