Building Deep Water Frame

[Alan McKnight]

I am looking for some information on building the deep water raft frame.

Can I take a 2x4 and dato the middle say an inch deep and 3/4 in wide and then insert 3/4" plywood , then do the same for the top board,  making like an "I" beam. Would this be strong enough to be a panel that will handle the weight and pressure of the gravel and water?

[TCLynx]

You have lost me?  Are you trying to build a Raft bed or a media bed?  I'm not quite sure what you mean by Deep water raft frame when you later ask if the I beam will be strong enough to be a panel that will handle the weight and pressure of the gravel and water?

If you are building a raft bed then you are really only dealing with the weight and pressure of water, not gravel.  If you are making something to be a "raft" then you would really only be dealing with the weight of plants and media in the net pots, not pressure or water.

[Alan McKnight]

TCLynx,  I guess I wasn't real clear was I.  I want to build media beds and also the raft beds.  I am just worried that the pressure on the plywood (I Beam) would be to much. 

[TCLynx]

How is your location as it relates to termites?  I'm not a big fan of lumber/liner beds in termite territory anymore.

 

What kind of liner will you use?  If you use DuraSkrim Liner and secure it along the top of the frame with a radius in the bottom corner the liner will actually pull down on the top rail rather than bowing the bed out.  However, if you do EPDM liner, it is stretchier and doesn't work quite as well that way.

Anyway, perhaps the duraskrim with radius could work attached to the I beam design you mention but it would work just as well or maybe even better if you skipped the plywood and just made a nice sturdy top frame out of 2x wood.

 

As I noted, I don't like lumber next to liner anymore after experiences with termites here in Florida.  So I use metal rails.  They cost more but I avoid having to replace the wood every few years (even pressure treated I haven't had a lumber/liner bed last more than 2 1/2 years here.)

[Alan McKnight]

Wow I never even considered the termite issue and in Calif, we have termites here for sure. I don't like the pressure treated wood as it has chemicals . Will keep looking.  How did you attach the liners to the metal pipe?

Thanks for the info.

TCLynx said:

How is your location as it relates to termites?  I'm not a big fan of lumber/liner beds in termite territory anymore.

 

What kind of liner will you use?  If you use DuraSkrim Liner and secure it along the top of the frame with a radius in the bottom corner the liner will actually pull down on the top rail rather than bowing the bed out.  However, if you do EPDM liner, it is stretchier and doesn't work quite as well that way.

Anyway, perhaps the duraskrim with radius could work attached to the I beam design you mention but it would work just as well or maybe even better if you skipped the plywood and just made a nice sturdy top frame out of 2x wood.

 

As I noted, I don't like lumber next to liner anymore after experiences with termites here in Florida.  So I use metal rails.  They cost more but I avoid having to replace the wood every few years (even pressure treated I haven't had a lumber/liner bed last more than 2 1/2 years here.)

[TCLynx]

I use Snap Clamps to attach the liner to the fence rails.  I don't recommend going much deeper than 12 inch deep beds for this type of construction since the snap clamps can only grip so hard.  You can add grip clamps over them or add a tech screw but still 12 inches deep is usually enough.