2008 March Lumber Talk.com: Professional-Level information and how-to-build articles for wood, timber, and lumber professionals and users. 2008 March » Lumber Talk

I made a sketchcast about how to build a wood bulkhead and I wrote about how to build a wood retaining wall but I might have assumed too much about how much you know about the bulkhead materials I listed. They are slightly off the beaten path from “regular” building materials you’d find at your local hardware store so here is a breakdown of basic wood bulkhead materials.

Wood Bulkhead Materials List

Building a wood bulkhead is similar to building a privacy fence. You have posts (pilings), rails (wales), and pickets (sheets or sheeting). A bulkhead typically has great horizontal force applied against it, though, so it has more structural requirements than a fence. In order of front to back (water side to ground side) the parts of a wood bulkhead are:

  • Pilings (can be round or square)
  • Wales
  • Center Match (sometimes call “sloppy tongue & groove”)
  • Filter Cloth
  • Tie Rods
  • Deadmen
  • Top Cap
  • All the required Hardware (nails, screws, spikes, nuts, washers)

Attention: First, the materials required for YOUR wood bulkhead might be different from those I am showing below so please have your bulkhead designed and specified by a professional builder and/or designer. Also, be sure to use the proper materials for the best longevity. Using cheap materials to save money NOW is only wasting money in the long run. Use properly treated wood, galvanized or stainless hardware, and make sure the bulkhead is installed properly.

Treated Pilings

You can use round or square pilings. It is totally up to you. You might want to match your neighbors’ bulkheads or you might be concerned about costs (round pilings cost less). Either way, use properly treated wood – 2.5 pcf in saltwater and a minimum of .60 pcf in freshwater. For brackish (mixed fresh and salt) water, go with 2.5 pcf.

Round pilings - small ones

treated 6x6 timbers

Wales

Wales are the horizontal boards (like the rails on a fence). Most wood bulkheads have two but some will have three or more. Wales are connected to the land-side of the pilings and will have the center match sheets nailed to them. A very common size used for wales is 3×8. You should use the longest lengths possible to minimize joints, which can become weak spots. You should be able to find 3×8-20’s from most marine construction suppliers. Many other sizes are commonly use depending upon the sizes of the bulkhead and the forces applied to it. I have seen wood bulkheads with 8×8 wales.

treated 3x8 rough lumber for wales

Center Match

Center match are sometimes called “sloppy tongue & groove” because the joint is a little loose to allow for swelling in the water so the edges will not break with regular expansion and contraction when the boards alternates between wet and dry.

Center match is usually nominal 2×10 with actual dimensions of 1.5″ x 8.9″. That is, because of the groove each board only spans 8.9 inches – very important to factor into your bulkhead materials list. I have heard of numerous people making an extra trip to the dealer (or paying for another delivery) because they were 5 pieces short of center match.

treated 2x10 center match

Filter Cloth

Filter cloth is kind of like a very thick felt. The purpose of filter cloth is to stop silt and dirt from seeping through the spaces between the center match while allowing water to drain and relieve hydrostatic pressure from the bulkhead after a rain – it helps maintain a cleaner appearance and keeps soil behind the bulkhead where it should be. While some people use plastic for this purpose, I truly believe a quality geotextile filter cloth is better because it allows the water to drain. Filter cloth is cheap – use it.

Geo-Textile Filter Cloth for a Wood Bulkhead comes in rolls

Tie Rods

Tie rods support the structure from behind to keep it from falling forward (into the water). Tie rods will be connected to the pilings on one end (via hold drilled from the front to back of each piling) and to deadmen on the other end. They are simply long rods with about 12″ of threads on each end for a nut.

Builders usually use tie rods that are about 3 times as long as the exposed height of the bulkhead being built. For example, a 4′ tall wall will commonly use 12′ long tie rods. The come in diameters including 1/2″, 5/8″, 3/4″, and larger. Some people use cables instead of tie rods but tie rods are stronger and they can easily be tightened if needed.

galvanized tie rods

Deadmen

I have no idea why deadmen are called deadmen but I can make up some good stories about medieval times and using what you have to protect the castle if you want. 🙂

Dead men are treated posts – round or square and often cutoffs – used to “tie back” the bulkhead and support it from behind. Like the rest of the materials, the size of the deadmen used should be based upon the overall height of the wall and the load it bares.

new dead men.  These might be cut in half for a small wall.

Top Cap

Most top caps are made using a regular S4S 2×12. While they are not required, top caps will provide a little more structural integrity while giving the wall a more finished appearance from above.

Hardware

Use galvanized or stainless steel hardware when building on or near water. Screws are better than nails but more time-consuming. Generally, you will need the following hardware for your bulkhead:

  • Tie Rods with 2 nuts and 2 washers for each
  • Spikes (60 penny nails) to attach the wales to the pilings
  • 16 penny nails (or larger) to attach the center match to the wales and the top cap to the wales
  • Staples to attach the filter cloth to the center match

The materials list for a wood bulkhead is pretty simple and short. The bulkhead materials listed above will work for most wood bulkheads or retaining walls built around residential locations. If you need a reliable source for wood bulkhead materials, call the people at Building Products Plus in Houston, TX who let me take the pictures above in their yard. They ship nationwide so you can call them from anywhere.

Here’s a simple sketchcast from WoodScience (became Lumber Talk) on how to build a wood bulkhead.

By Chris | March 13, 2008 - 3:10 pm - Posted in Specs & Data, Structural Components

Dominion Truss, a roof truss manufacturer in the northeast, has this great page of truss terms, giving a definition of the parts of almost any truss design.? They make pressed/manufactured roof and floor trusses for “large and complex” commercial and residential projects and have fairly sophisticated design capabilities as well.

Here is their list of roof truss terms.? You can also read them on their site.

Allowable Stress: The amount of force per unit of area permitted in structural member. Values for allowable stresses of wood can be found in “National Design Specification Supplement Design Values for Wood Construction.”

Allowable Stress Increase or Duration of Load Factor: A percentage increase in the stress permitted in a member, based on the length of time that the load causing the stress acts on the member. The shorter the duration of the load, the higher, the higher the percentage increases in the allowable stress.

Axial Force: A push (compression) or pull (tension) acting along the length of a member. Usually measured in pounds, kips (1000 lb.), tons (2000 lb.) or the metric equivalents.

Axial Stress: The axial force acting at a point along the length of a member, divided by the cross-sectional area of the member (usually measured in pounds per square inch).

Beam Pocket: A void or cutout built into truss to allow beam support.

Bearing: A structural support, usually a wall or beam, that occurs at the top or bottom chord of a roof or floor truss.

Bending Moment: A measure of the bending effect due tot he live load and dead load on a given truss chord member.

Bending Stress: The force per square inch of area acting at a point along the length of a member resulting from the bending moment applied at that point. Usually measured in pounds per square inch or metric equivalent.

Bottom Chord: A horizontal or inclined (e.g., scissors truss) member that establishes the lower edge of a truss, usually carrying combined tension and bending stresses.

Built-up Beam: A single member composed of two wood members stacked on top of each other and fastened together with connector plates, for the purpose of crating additional strength and stiffness.

Butt Cut or Nub Cut: Slight vertical cut at outside edge of truss bottom chord made to ensure uniform nominal span (usually ¼ inch).

Camber: An upward vertical displacement built into a truss bottom chord to compensate for deflection due to dead load.

Cantilever: The condition where both top and bottom chords extend beyond a support with no bearing at the extended end.

Chase Opening: An open panel in a floor truss for the purpose of running utilities through it, such as heating and air conditioning ducts.

Clear Span: Horizontal distance between interior edges or supports.

Combined Stress: The combination of axial and bending stresses acting on a member simultaneously, such as occurs in the top chord (compression + bending) or bottom chord (tension + bending) of a truss.

Compression: Force exerted on truss member that has a compressive or pushing effect on the member and its respective end joint.

Concentrated Load: Superimposed load centered at a given point (e.g., roof-mounted air conditioners).

Dead Load: Any permanent load such as the weight of the truss itself, purlins, sheathing, roofing, ceiling, etc…

Deflection: Movement of a truss (when in place) due to dead and live loads.

Design Loads: The dead and live loads, which a truss is designed to support.

Dual Pitch Truss: A truss that has two different pitches on its top chord.

Facia: Trim board applied to ends of overhang.

Force Diagram: Graphical solution of axial forces as they interact within the members of a truss.

Heel: Point on truss at which the top and bottom chords intersect.

Heel Cut: See Butt Cut.

Interior Bearing Truss: Truss with structural support in the interior truss span as well as at end points.

Lateral Brace: A member placed and connected at right angles to a chord or web of a truss for the purpose of providing lateral support.

Level Return: Lumber filler placed horizontally from the end of an overhang to the outside wall to for a soffit.

Live Load: Any loading which is not of a permanent nature, such as snow, wind, temporary construction loads, etc…

Nominal Span: The horizontal projection of the bottom chord of the truss.

Overhang: The extension of the top chord of a truss beyond the bearing support.

Panel Length: The center line distance between joints measured along the chords.

Panel: The chord segment defined by two succeeding joints.

Panel Point: The point of intersection where a web (or webs) meets a chord.

Peak: Point on truss where the sloped top chords meet. The highest point of the truss.

Plumb Cut: Top chord cut to provide for vertical (plumb) installation of facia.

Purlin: A horizontal framing member used to support sheathing or decking between two main load carrying structural members.

Reaction: Total load transmitted to its support by a given truss.

Saddle: An area where an additional roof slope and a ridge are created to facilitate drainage. Usually found behind vertical obstructions in the roof.

Stress Rated Lumber: Lumber that has been graded either visually or by machine by an approved grading agency and assigned allowable working stress values. All lumber used in engineered wood products such as trusses must be stress rated.

Scupper: An opening in a roof or parapet usually faced with metal flashing to drain water from the roof at a given point.

Sealed Drawings: Drawings prepared, checked, and/or approved by and having the seal of a registered professional architect or engineer.

Slope: (Pitch). The inches of vertical rise in 12 inches of horizontal run for inclined members (generally expressed as 3/12, 4/12, 5/12, etc…).

Splice Point: (Top & Bottom chord splice). The point at which two chord members are joined together to form a single member. It may occur at a panel point or between panel points.

Split Truss: Trusses used where fireplace intersects the truss span, parallel or perpendicular to the truss in the middle or inside of the house. A split truss can be defined also as a stub truss if it is longer than one-half the span or as a monopitch truss if less than one-half the span.

Square Cut: End of top chord cut perpendicular to the slope of member.

Tension: Forces being exerted on a truss member that creates a pulling apart of elongating effect.

Top Chord: An inclined or horizontal member that establishes the upper edge of a truss. Usually carrying compression and bending stresses.

Truss: An engineered pre-built structural component designed to carry superimposed dead and live loads. The truss members are coplanar and are usually assembled such that the members form triangles.

Uniform Load: A total load that is equally distributed over a given length, Usually expressed in pounds per lineal foot (plf).

Valley: A depression in a roof where two roof slopes meet.

Webs: Members that join the top and bottom chords to form the triangular patterns that give truss action, usually carrying tension or compression stresses (no bending).

You can learn more about the parts of structural timber truss on WoodScience (the old LumberTalk.com).

By Chris | March 10, 2008 - 10:10 pm - Posted in Alternative Materials, How To

According to Google, the current conversion rate of British Pounds to US Dollars is 1 to 2.013 – yikes.

The Galloway home, a small cottage in southern Scotland, was built by Steve James for 4,000 Pounds (about $8,000). It began as part of project to help first time home buyers get their homes started and became an excellent experiment in just how cheaply a house can be built.

Construction actually began in 2004 when a foundation and heavy rains were erected. Those had to be demolished, though, because of heavy rains and failed tarps. The project was restarted in 2007 and recently completed.

Rock foundation with wood frame

straw walls with window framesVisible rafters hold up the turf roof interior

The rock foundation holds a traditional wooden frame of joists and stringers. The walls are made largely of straw bales and the roof is made of turf. Some of the materials are salvaged (such a window and door) and some were cut from local trees. While the price is low, it is a very different and slightly more crude project than typical small home plans, which are designed to be small and refined while reasonably affordable.

Here’s a Breakdown of the Costs (in £)

 

£600 supplies for volunteers

£500 sarking

£400 floorboards

£400 pond liner

£300 straw

£200 plumbing

£150 reclaimed joists

£150 plywood

£150 equipment hire

£150 glass

£100 quicklime

£100 wiring

£100 tarpaulin

£100 paint/varnish

£100 batteries

£100 fixings

£100 miscellaneous

£100 fuel for power tools

£70 water pump

£50 water heater

£50 stove chimney

£30 cooker

It is an inspiring idea, really. I doubt that houses of mud and straw will start appearing on every street corner but the possibility of an ultra-inexpensive house looks more realistic. We could all have our Walden if it weren’t for local and state build codes, right?

By Chris | March 5, 2008 - 2:11 pm - Posted in Decks & Fences, How To, Plans, Treated Wood

How to Build a Fence that Lasts

Building a wooden fence can be backbreaking work but, conceptually speaking, it is very simple. You choose your layout, mark your corners, stretch a string to keep your lines straight, set your fence posts, add rails, add a gate, add pickets, and you are done. Again, at its core…

Here’s some help if you are building your fence on a slope.

How to Build a Fence (the basic version)

  1. Choose Your Fence Layout
  2. Mark the Fence Corners
  3. Stretch a String Between Corners
  4. Set Your Fence Posts
  5. Add Fence Rails
  6. Add Gate
  7. Add Fence Pickets

How to Build a Fence that Will LAST

The main point of this article is about how to build a fence that will last. There are a few things you can do to build a fence that will outlast the other fences in the fence line. Your neighbors will be replacing old worn out fence materials while you sit atop your fence saluting their hard work and poor construction methods.

Building a long-lasting fence can also be broken down into a short list similar to the one above but with a few additional details…

Steps to Build a Fence that will Last

  1. Choose Your Fence Layout (same)
  2. Mark the Fence Corners (same)
  3. Stretch a String Between Corners (same)
  4. Set Your Heavily Treated or Coated Fence Posts
  5. Add 3 Fence Rails (not two) Using Screws
  6. Add a “Rot Board”
  7. Add Gate
  8. Add Fence Pickets Using Screws

fancy wood fence

 

The builder of this fence went for longevity using .60 CCA treated 6×6 posts and a “rot board.” The fence also looks beautiful because of the trim boards at the top and the fact that the rails and pickets are set inside and between the posts. This can be done using 4×4 posts but it looks funny because the posts are so small (relatively).

There are three main components of any project. In no particular order of importance, they are:

  1. Design
  2. Materials
  3. Construction

Each of these three components must be respected for any project to produce a strong and long lasting result. Building a fence is no different. Taking these components into account, here’s a brief overview of what you can do to build a fence that will outlast your expectations. It is easiest to analyze proper fence construction at the components level.

Think Longevity by the Piece

Design your fence with longevity in mind. A fence is only composed of four basic components:

  1. Posts
  2. Rails
  3. Pickets
  4. Fasteners

Build your fence so that each component supports, and is supported by, the components around it. Think about how you want the fence to look five years from now as you design it, buy your fence materials, and build it.

Fence Posts – A Strong Foundation

Posts rot at the ground line so protect against that. Use posts that are well treated and come from a reputable location. For the absolute best results, use posts coated with a polymer coating such as the ones produced by the folks at American Pole and Timber. They coat the bottom three feet of treated posts with a polymer coating that is guaranteed for 25 years. 4×4-8′ posts cost about $17 each instead of $8 but you will probably be able to use the posts again for your next fence – saving you time and headaches down the road.

Other long lasting fence post tips include:

  • Plant deeply – about 1/3 the height of the fence.
  • Tamp the bottom of each post hole to minimize settling over time.
  • Encourage drainage with a thin layer of gravel (a few inches is fine) at the base of the posts.
  • Level carefully to ensure the posts well aligned and straight.
  • Pack the dirt tightly around the posts after they are installed.
  • Cap, slant, or round the top of each fence post so water cannot accumulate.

Whether or not you want to set your posts in concrete is up to you. While concrete makes a post seem permanent I am not convinced it actually makes the fence last much longer and it definitely makes removal a real bear.

Along the same vein, you can also consider using larger fence posts such as 6×6’s. The look cool, are really strong, and are usually treated more heavily that 4×4’s. They also require larger holes and are very heavy so you will probably need help putting each fence post in place. Are they necessary? Probably not but they will provide an excellent foundation.

Fence Rails – Use Three

Rails sag over time and there two are primary ways you can combat this – build with your rails on their “edges” so you will have a stronger “depth-of-section” and use three rails so each rail supports less weight. A third option is to set the fence posts closer together. Always use treated wood. #2 grade treated lumber is great for a fence – cost effective and strong.

If you get nothing else out of this how to article, take this away – use three rails. Pickets have a weakness that shows up over time but is seldom considered when the fence is being built. Pickets have a tendency to warp. Using three rails dramatically improves the chances that your fence’s pickets will remain straight.

how to build a 3 rail picket fence

Use 3 Rails when Building Your Fence

Toenail your fence rails to your posts. Not only does it look better than butted rails but it leaves no spaces between pickets and rails where grass can grown and critters can hide. Birds and other nesting animals often build homes in the spaces between posts and pickets, especially in “neighbor friendly” fences with alternating panels.

fence rail types

 

I prefer to “toenail” fence rails because this method creates straighter lines and does not leave a space for grass, weeds, and critters to creep between the posts and the pickets.

Fence Pickets – Lift & Support

Most pickets come in 5/8″ thick but use 3/4″ thick pickets if you can find them. That would be the same as using 1″ nominal dimension lumber. Call around the local lumber yards. Yes, the will cost a little bit more but will last longer, warp less, and look better.

Make sure you use treated pickets. A good treated picket will last 10 years if maintained with the occasional stain. An untreated picket will last only a few years. This should not be a big concern because you usually won’t even find UNtreated pickets – there’s no point in making them. You can also consider cedar, redwood, or any other variety of “naturally resistant” wood species.

The best two things you can do to extend the life of fence pickets are to use a rot board and a three rail system. Again, if you take nothing else away from this article…use three rails. The rot board lifts the fence pickets off the ground where they are in contact with pests and moisture and keeps them aways from regular beatings by a weed eater. A three rail systems supports fence pickets more effectively to minimize warping.

Fasteners – Use Screws

Use screws for everything. Good deck screws such as Primeguard Plus coated deck screws do not rust and will not pull out like nails. Building your fence with screws minimizes warping and helps keep your fence solid and tight. When building your fence gate, use excellent hardware – not the cheapest kit you find. Use galvanized or zinc coated hinges and hardware to minimize rust.

Fence Maintenance

Now that we have gone over the basics of how to build a fence that will last, let’s look quickly at fence maintenance. There’s not a lot to do, really. Just spray the fence with a great high quality deck and fence sealer every few years and you should be great. A few of the best brands are Cabot and Wolman, according to a Consumer’s Report article as well as my experience.

Examine the fence occasionally for broken boards or sagging rails. If one rail is sagging, it is not properly supporting the components around it. Replace broken boards. Not only do they look bad but when they flop back and forth, they put unwelcome stress on the rails.

A long-lasting fence will cost a few dollars more up front but you will save money in the long-run because it will last longer and you might even get to re-use your fence posts. Most fences are still in service looooong after their aesthetic life died a slow miserable death. Another benefit of a well-built fence is that it will always look good.

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