2nd A/C without existing provisions

[kellertx5er]

I have read many posts about adding a 2nd a/c in rigs with rough-in provisions for it. My trailer has none. Anyone out there who has cut their own roof opening and added a unit? Would love to hear your stories and advice, especially about bracing the roof structure and keeping the ceiling looking nice.

Not looking for any electrical advice, I am well schooled in that department.

[rickhise]

In the mean time try a free standing unit
You can modify a opening to draw in
Fresh air. Run a drain hose to expel the condensation
Or depend on auto shut off drain pan.
Not what you ask but they are powerful efficient
Cool an so user friendly

[Ron_Nielson]

You probably have this all wrapped up by now. Pls let us all know what you decided to do. And let us know what trailer make/model you are working on.

My trailer had a vent in the bedroom so I used that opening to add my bedroom a/c unit. They didn't do any super job in framing the vent,1 frame around the top, one around the bottom,but I weigh 250 and the roof seems to be fine with me walking on it, so why not a 90 lb a/c unit? I did add some stiffening/finishing just to make me happy. All turned out OK.

Assuming you have at least 14" or 15" between joists, it should just be basic carpentry that you should be able to do from your bedroom ceiling access you would have to cut, or the roof access. Personally, I'd go in from the bedroom side, make sure you can tie everything together properly, then you can cut your roof hole when it's convenient. I'd much rather patch in the bedroom, IF NECESSARY, than the roof.

[kellertx5er]

Was hoping to get feedback from someone who had actually done it.
Ceiling will obviously have to come down, at least partially.

[westend]

Boxing off the opening won't be that difficult if you have wood roof trusses. If it was me, I'd probably add a second pair of braces to insure the trusses bearing the weight would stay stable. If you have an aluminum truss, bracing gets a bit more complicated since you will be using some form of bracket that attach to the aluminum truss.

[eHoefler]

kellertx5er wrote:

eHoefler wrote:
The added bracing required for the weight of the unit will not be there. I would not do it.

I plan to add bracing. Was looking for suggestions such as adding doublers to the joists.

Most trailer bumpers are not constructed for towing or adding bike racks, yet many people modify them to perform.

In order to properly brace it, you would need to open the ceiling wall to wall or peel the roof off. You will need to add bracing to the trusses/roof roof structure from wall to wall. It is not simply adding blocking between trusses.

[kellertx5er]

eHoefler wrote:
The added bracing required for the weight of the unit will not be there. I would not do it.

I plan to add bracing. Was looking for suggestions such as adding doublers to the joists.

Most trailer bumpers are not constructed for towing or adding bike racks, yet many people modify them to perform.

[kellertx5er]

As I said, there are no provisions of any kind- no vent opening, no electrical. Not concerned about electrical, already have a plan.

[rhagfo]

Question, the bedroom doesn't have a ceiling vent in it??
If not may be difficult to connect two roof ribs to create the necessary 14" sq opening.

[Chris_Bryant]

If there is a ceiling light in the area, cut a hole under it to explore. A lot depends on roof construction- loose fiberglass insulation will be far easier to deal with than laminated foam, which would be very difficult to reinforce.
Next, you have to find out what wiring is in place that might need to be rerouted.

[eHoefler]

The added bracing required for the weight of the unit will not be there. I would not do it.

[Toddupton]

The hole in the roof is the easy part it's the getting 120 v power to it that makes it interesting.