How to cut a wall and create an access panel for plumping

Repair help for the do-it-yourselfer.
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Moderators: Greg, Mark, mhrAJ333, JD

Posts: 17
Joined: Tue Apr 08, 2014 8:27 am
Location: WA State

Sun Dec 18, 2016 7:56 pm

First, I have to thank the fine people who contribute to this board. Ive owned my 1990 double wide for two years and have did several updates excluding the bathroom since having purchased, moved and set it up on my property.

Which leads me to my latest project...a cracked and leaky plastic bathtub ( drain mostly). My plan is to cut into the wall directly behind the plumbing which happens to be the spare room conviently. Im considering cutting a decent size access panel as I need to access the plumping (shower & faucet) and drain. My suspicion is what I have read on here is that the support underneath has given away. I plan to purchase a new tub and enclosure and use the existing drain and install new shower head and faucet. 'This will be followed by me cutting and removing the belly and replacing insulation and cover. I need to wait until the weather breaks before opening up the belly...perhaps spring time ;-)

My question to you wonderful people is:

1)How big of an access door do you think I should cut to access plumping including drain?
2) Best way to cut the wall board.?

(My walls are pressed wall board with the curved edges ( not sheetrock) and my studs are very inconsistent in spacing.). I actually considered hammering a guide and cutting with my drummer like tool that will cut a decent straight line in wood. Perhaps a chalk line as well. I'm at a loss as this is a project Ive never tackled. I've flipped several homes over the years...but never a manufactured one. The learning curve has been steep .

Thanks again for your invaluable advice and help.

User avatar
Posts: 5673
Joined: Wed Feb 28, 2007 8:01 pm
Location: Weedsport, NY

Sun Dec 18, 2016 9:11 pm

Since you are replacing the tub, use a sawsall and cut the old tub apart. Then you can get a better idea of what you will need to access the drain to connect the new tub, usually from under the home through the belly.
For the faucet you can measure the location on one side of the wall and transfer to the other side and cut your access panel. Or you may get lucky and be able to carefully remove the whole panel and screw it back in place.

"If I can't fix it, I can screw it up so bad no one else can either."

Posts: 238
Joined: Tue Feb 26, 2008 8:33 am
Location: Anna, Tx

Mon Dec 19, 2016 6:08 pm

Is this just a tub or a tub/shower enclosure? If it is a tub/shower, it probably has the plastic walls as well, so do as Greg recommended and cut the existing unit into pieces for removal. Once the 'tub' and 'wall panels' are removed, you should have access to all of the plumbing as the original builder probably did not finish the wall if a tub/shower was going in. Believe me - they cut corners wherever they can!

(I had to replace the faucet on mine - and cut an access panel in the adjacent bedroom. I started small and then opened it up once I could see what was behind the drywall. And, the one thing I noticed was there was zero drywall/paneling on the bathroom side of the studs.)

With everything out of the way, you can better design an access panel to address any future issues.
Opportunity has a shelf life.

Posts: 383
Joined: Mon Oct 25, 2010 9:53 pm
Location: Steuben County, NY

Tue Dec 20, 2016 9:41 pm

Check a home center - there are access doors available to install for easy access. They can be painted to match your walls. If you go that route, size your cuts accordingly.

Posts: 47
Joined: Sun Apr 27, 2008 7:12 pm
Location: Abbottstown, Pa

Sat Dec 24, 2016 11:06 pm

I had my home replumbed years ago. They removed a whole panel in a closet for access to the small bathroom tub/shower and cut a door sized panel in the master bedroom to access the master bath garden tub. They finished off the opening with door frame molding so it doesn't look too bad. I have plans to make a feature wall there with hidden access to the panel should it need to be removed again.

Posts: 17
Joined: Tue Apr 08, 2014 8:27 am
Location: WA State

Sat Dec 31, 2016 7:55 am

Update and photos. I was pleasantly surprised to find that the floor under the tub was not rotten as I suspected. The insulation around the drain is moist and I'm leaving the whole open to dry out. I will probably pull out what I can reach and replace with new today. I was also surprised to find plywood behind the bathroom board. I haven't cut the access door for the other side yet. I plan to move the shower controls up to a normal spot and instead of installing a shower enclosure I plan to install the new tub and tile the wall. I will install hardy board. I found a small tub on Home Depot's site for $150.00 which is a bit short, but I will build a small wall to use as a soup holder. I will keep you posted as I continue with this project. Thanks again for the advice and any other ideas are greatly appreciated. Oh, Lastly I think I will tile tot he ceiling as the walls are not Sheetrock, but old wall board. Thoughts on how that looks and works?

I tried to upload photos but it says the file is too big. I will try to figure out how to shrink the file.

Posts: 110
Joined: Sat Oct 08, 2011 11:39 am
Location: Brazil, IN

Sat Dec 31, 2016 9:04 am

Tile? Good luck with that. I can guarantee it will look GREAT once it's done. I can also guarantee that at some point the trailer, no matter how well it is set, will shift and tile will fall (even if you use hardy board). It's the nature of a mobile home.


Posts: 17
Joined: Tue Apr 08, 2014 8:27 am
Location: WA State

Sat Jan 07, 2017 9:53 pm

Thanks for the encouragement. Interesting about the hardy board. I agree with the settling problem. I plan to level the house before I's already settled some. I will also make sure I keep extra tiles for later.
Thanks so much!