Alumi-Span – Installation

Installing a Basic Dock


When you receive a dock from Alumi-Span you will receive a kit. A basic dock kit will include dock sections, cross arms, upright post, bottom plates, stringer brackets, and caps for the post. The first thing you should do is pre-assemble as much as possible. In subsequent years you will not have to do this preassembly.


  • Start with the cross arms, which will already have the post clamps on them. Take the stringer brackets (100B) and attach 1 to each end of the cross arm. Don’t tighten them completely at this point. Set it aside.
  • Take all of the bottom plate halves and using 2 carriage bolts loosely connect the halves together.
  • Now put the upright post into the plates. Leave 2-3 inches of the post sticking beyond the bottom of the plate unless you are on rocks. This will make the dock even more stable.
  • Now that you have the post with bottom plates assembled, loosen the clamps on your cross arm, slide the posts in to the desired height and just snug the bolts back up. It is easy to adjust the height once the dock is in place so for right now having the cross arms at approximately the right level is fine.
  • You now should have what looks like an “H”; we call this a standard assembly. The only thing left will be the caps for the post and you want to wait until the very end of the project to put them in.


Standard Assembly

  • You are now ready to install the dock. Have someone help you lift the first section to the lake the beginning of which will normally sit on a break wall or directly on the shore. Next lift the other end of the first section up and slide the first standard assembly under it.
  • You will now loosely fasten the stringer brackets to the section by putting one 1” hex bolt into each side, the holes should line up. Assuming you are going to have more sections, position the assembly so that two sections can share the stringer brackets.
  • At this point you can adjust (or ramp) this section up or down to the level you will use for all other sections but never ramp more than 8” per section. IMPORTANT: The dock must be high enough to never allow waves to go over it. On a small lake this could be as little as 8” but on a very large lake or a lake with changing water levels this could be as much as 2’. Neighbouring docks can give you a good idea of what is appropriate.
  • Take the next standard assembly and walk it out into the water. Make sure it’s close to level with the section you just put in and set it the length of the section away from the last one.
  • Either float or carry the next section out and put it onto the other half of the previous standard assembly.
  • Repeat steps 9 and 10 until you are done but on the last section the standard assembly will be placed behind the dock end to make room for a cap and you will only use one set of stringer bracket holes.
  • Once the dock is in place you will want to make sure it is level. Level it by loosening the bolts on the 300C castings. The pole will easily slide up and down. A small level used in both directions works good but measuring to the water is even better if the water is calm. Once level tighten the 300C back up.
  • Now go around and all tighten all the bolts. The stringer brackets (100B) are the main suspects here. You need to tighten the bolt’s attaching them to the dock and the two bolts holding your stringer bracket to the cross arm.
  •  You now should have a completed basic dock install. Let the dock settle for a few days, if it’s still level, you may want to trim the tube all to the same level with a 2” tube cutter (they can be purchased inexpensively at Lowes or Home Depot) and finally push the black post caps in.

NOTE: Number the standard assemblies with a magic marker so that next year they go in exactly the same way.



Installing a Basic Dock with Augers


Augured installations are similar to the bottom plate instructions above but with some differences.


  • Instead of completing the standard assembly as above, you want to first preassemble the augers into the poles.
  • Next, attach the cross arm assembly complete with stringer brackets (but without poles) to the end of the section to be installed using two 1” bolts provided. Remember that except for the last section the cross arm will stick out beyond the end so it can share the next section.
  • Walk the section with out to the water and prop up the end. A vertical pole with a stringer bracket mounted temporarily to it can be handy for propping up this end or just have another person hold it up.
  • Take the clamp(s) off the cross arm assembly and hold the first auger pole about 1/8” away from the one of the ends. Make sure the poles are vertical (holding it loosely from the top, let gravity make it vertical). Auger the pole about 1’ into the ground (plus the auger), or until it starts to turn fairly hard. At this point you can now put the clamp back on and tighten it up. Repeat this process for the other side. With augured poles you can adjust the height simply by auguring more or less; therefore you can put the caps on immediately. Typically you use an inexpensive turn bar to auger but if you have several poles to auger, a pier post ratchet saves a lot of work. Caution: Don’t use any type of pipe or other locking wrench as that will leave sharp burrs on the pole.


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