Tips for removing plywood under AC + Heater tubing?

[Chad1865]

Does anyone have tips for removing the old subfloor out from under the factory AC and heater coolant lines?

I want to keep the AC and the heater but also replace the old plywood in these areas. Unfortunately, their coolant lines seem to be fed through holes drilled in the plywood. It doesn't look like I can simply pull out the plywood without damaging the lines.

I don't have much mechanical experience, so unclipping the lines to remove the plywood feels beyond me.

Here is a picture of the housing on the AC lines and plywood around them. Similar setup on the opposite side of the back door for the heater.

 

[family wagon]

First step is to loosen those things from the floor. Hopefully you can massage enough slack in the tubes and wires to allow moving them around a little.

Next is to break out the old wood. I like to use a reciprocating saw with a hook-tip blade to make plunge cuts into wood. The same could be done with a hand saw of the right size. Break up the wood with a chisel (or screwdriver) if a saw isn't an option. With this technique you can make cuts leading away from the holes in the wood and remove the wood in pieces. Basically you're extending the round hole until it reaches an edge of the board. Then the pipe isn't captive in a closed hole anymore.

Some of these Sawzall blades have the hook style tip I'm referring to (first and fifth from the left, and the one at the bottom).

Fitting new wood in is a bit of a trick, but it's more or less the reverse: take a solid sheet, make holes in the right places, then make cuts that cross the holes so that you can fit the wood into place in two or more pieces.

It can help to make a template of cheap material and transfer the pattern onto good wood when the template fits right. Cardboard and heavy paper are great materials. A roll of the brown or red builder's paper or rosin paper for protecting floors is perfect: cheap, rugged, and easy to manipulate with a knife or scissors. Keep in mind that templates can be made in many pieces and taped together: they don't have to look pretty, or even turn out perfect on the first try.

 

[o1marc]

The heater lines are just 1' heater hose help on with hose clamps. Once the cover is removed the lines can be pulled back through the holes with ease. Don't have AC in mine so can't comment on how they mount.

 

[Chad1865]

First step is to loosen those things from the floor. Hopefully you can massage enough slack in the tubes and wires to allow moving them around a little.

Next is to break out the old wood. I like to use a reciprocating saw with a hook-tip blade to make plunge cuts into wood. The same could be done with a hand saw of the right size. Break up the wood with a chisel (or screwdriver) if a saw isn't an option. With this technique you can make cuts leading away from the holes in the wood and remove the wood in pieces. Basically you're extending the round hole until it reaches an edge of the board. Then the pipe isn't captive in a closed hole anymore.

Some of these Sawzall blades have the hook style tip I'm referring to (first and fifth from the left, and the one at the bottom).

Fitting new wood in is a bit of a trick, but it's more or less the reverse: take a solid sheet, make holes in the right places, then make cuts that cross the holes so that you can fit the wood into place in two or more pieces.

It can help to make a template of cheap material and transfer the pattern onto good wood when the template fits right. Cardboard and heavy paper are great materials. A roll of the brown or red builder's paper or rosin paper for protecting floors is perfect: cheap, rugged, and easy to manipulate with a knife or scissors. Keep in mind that templates can be made in many pieces and taped together: they don't have to look pretty, or even turn out perfect on the first try.

FamilyWagon, thanks so much for your helpful tips. I especially appreciate a full explanation that's not too technical for folks like me

Widening the hole makes sense!

I have a reciprocating saw, I'll have to check what kind of blade it has. If not a hook-tip, I'll pick one up. The bus is at the mechanic right now, but I can't wait to try this out.

Testing out the new templates will be a fun game. :biggrin:

 

[Chad1865]

The heater lines are just 1' heater hose help on with hose clamps. Once the cover is removed the lines can be pulled back through the holes with ease. Don't have AC in mine so can't comment on how they mount.

Thanks, Marc.

Just so I'm following -

Do you mean the cover on the heater or the hose? I have the hose cover off, but haven't tried taking apart the heater yet. It unscrewed from the wall/floor in one big unit.

Once the hose are disconnected from the heater unit, do they automatically start bleeding coolant? Will I need to fully bleed the lines or just keep some clamps handy?

 

[o1marc]

Thanks, Marc.

Just so I'm following -

Do you mean the cover on the heater or the hose? I have the hose cover off, but haven't tried taking apart the heater yet. It unscrewed from the wall/floor in one big unit.

Once the hose are disconnected from the heater unit, do they automatically start bleeding coolant? Will I need to fully bleed the lines or just keep some clamps handy?

the cover on the hose. There are 1" pipes going into the heater that the hoses just plug onto and then clamped.