Trailer roof mount a/c bracing

[matt2212]

I was looking at a roof mount a/c unit and was told that the cross beams may need braced around the hole to support the ac. It seems that it will sit across a few of the roof beams and have been told by some that it is plug and play, others to brace it.

What does everyone think? I thought about welding some angle steel so they sat on either side of the hole.

any ideas or perhaps pic's

 

[matt2212]

Not good pics but this is what is there

 

[dbakerpa]

I actually had an RV guy look at mine-before i realized how much the AC cost. He said I could mount it right at my vent opening without an issue. you could always add some angle and self tappers to the long runs if you were worried. I tend to over build everything because of ol murphy.

 

[HokieRider]

i would brace it. Not so much because of the weight, but because of the wind resistance. The last thing you need is for it to rid through the fiberglass at 75mph. Besides it wouldn't take much bracing and its better to be safe than sorry.

I would probably go with 2 pieces of aluminium angle (maybe 3/4 in). Just run them across the existing roof beams to tie it all together. Just do whatever you can to spread out the load of the unit.

 

[luded1]

needs to be braced.

 

[xrated]

If you have a standard roof opening for a vent, there should, and I repeat.........should be a roughly 14" x 14" opening there. If the opening is a square, as in the tubing on all four sides of the opening, you should be fine. When I bought my trailer, I had a roof vent put in from the factory, knowing that at some point in time, I would remove the vent and put an A/C rooftop unit in. I installed one this past spring on my trailer and the old vent came out and the new A/C unit fit right in the same hole. Once the unit is in place, and centered in the opening, you have a metal, inner square piece that screws to the base of the A/C unit and it is very secure. Hope this helps.

 

[JU190]

My trailer also came with a roof vent and was already braced with a 14x14 metal frame.
Unbolt the roof vent and in went the AC, 4 bolts hold the AC on.

 

[HaVoC]

Brace it, I personally wouldnt scrap the roof vent! U need ventilation. Not to mention if u store gas in the trailer. Most trailers that have rooftop ac's have flat a flat roof.Do it right the first time around and dont look back.

 

[matt2212]

HaVoC;243470 wrote: Brace it, I personally wouldnt scrap the roof vent! U need ventilation. Not to mention if u store gas in the trailer. Most trailers that have rooftop ac's have flat a flat roof.Do it right the first time around and dont look back.

I thought about this and may cut a new hole you make good points

My vent is centered between roof beams on 20" centers so from what I see I will need to build a frame to Spread some load out

The best option may be to start from scratch and keep the air vent in place


Thank you everyone

 

[Kegger]

You MUST add bracing! Dont underestimate how much that trailer is gonna bounce that 120lb. boat anchor sitting on top. I used 1-1/2" angle steel on both main cross members that support the unit. Cant show pics because I just started putting the ceiling in and covered it already -sorry.

 

[matt2212]

Kegger;244309 wrote: You MUST add bracing! Don't underestimate how much that trailer is gonna bounce that 120lb. boat anchor sitting on top. I used 1-1/2" angle steel on both main cross members that support the unit. Cant show pics because I just started putting the ceiling in and covered it already -sorry.

This is the route i will go..

What did you use for the ceiling? and did you insulate the roof first?

I was thinking foam carpet pad. its treated to not mildew ( my roof shows condensation on a cool morning) and has some R value

 

[HaVoC]

Get some energy shield and call it a day

 

[matt2212]

so just a layer of this stuff and thats it? where do i get it

 

[HaVoC]

matt2212;244372 wrote: so just a layer of this stuff and thats it? where do i get it

Matt, goto lowes,homedepot. It comes in sheets like sheetrock,U can get the regular stuff or they have it where on side has foil.I would just get some R7. Cut it fit it in between the cross members and your done.Use any silicone or chaulk to hold it to the roof.If u want to finish it off with cheap luan plywood u can or leave it and go racing..

 

[JohnS]

I used this to insulate the ceiling of my trailer and wow did it make a difference. Don't get me wrong if it is hot ouside it gets hot inside but this stuff keeps the inside of the trailer from turning into an oven. http://www.homedepot.com/Building-Materials-Insulation/Owens-Corning/h_d1/N-5yc1vZasbsZ3q5/R-100320343/h_d2/ProductDisplay?catalogId=10053&langId=-1&storeId=10051&superSkuId=202938960

I cut it to fit inbetween the beams s touch big and and wedged it in, then went around the edges with black RV Silicone that made to deal with the weather including high heat. I can take a pick tonigh if you like.

John

 

[dbakerpa]

JohnS;244400 wrote: I used this to insulate the ceiling of my trailer and wow did it make a difference. Don't get me wrong if it is hot ouside it gets hot inside but this stuff keeps the inside of the trailer from turning into an oven. http://www.homedepot.com/Building-Materials-Insulation/Owens-Corning/h_d1/N-5yc1vZasbsZ3q5/R-100320343/h_d2/ProductDisplay?catalogId=10053&langId=-1&storeId=10051&superSkuId=202938960

I cut it to fit inbetween the beams s touch big and and wedged it in, then went around the edges with black RV Silicone that made to deal with the weather including high heat. I can take a pick tonigh if you like.

John

I did the same and then put FRP board over that it gives a nice cleanable finish. Another trick is to put the white polymer roof coating on the trailer-like is used on mobile homes. It is reflective enough to decrease the heat inside. I definitely agree with the reinforcement. I would be worried about hitting a hard bump.