They cut open the belly to release a lot of water throughtout the home and now are repiring it by putting in new insulation and screwing a piece of scrap paneling to the boards. Under the paneling is exposed insulation.
I am not paying a professional. The maintenace men in the park are fixing it at no charge
While the paneling would be strong enough to hold just insulation… it is not a vapor barrier! A mobile home NEEDS that vapor barrier to prevent moisture from entering the home from underneath.
I have made repairs like this myself, MANY times… there is NO REASON why it should not be done properly.
Whatever caused the leak in the first place should be repaired.
All of that wet insulation should be replaced (as stated).
The underbelly should be resealed wherever it was cut open, replaced if necessary. Underbelly plastic can be purchased at any mobile home supply company. Let me re-emphasize, it needs to be SEALED.
Whenever I have had to cut into the underbelly, I have always stitched the flaps of underbelly back together with a HIGH quality duct tape, and then used contact adhesive (applied to the new patch, and the underbelly seam) to glue the new piece over the cut. Never rely on just duct tape, and make sure that the glue has flashed off before attaching the new piece over the seam. The duct tape helps hold the seam together, while the glue is applied to both pieces. I have seen repairs where a service tech used only duct tape, and in 6 months, it was down. Your repairmen will tell you that the scrap paneling will hold better than any duct tape… and it will… but it will not seal out the moisture that naturally comes up from under the home. You should have a properly sealed patch over the hole or seam cut into the underbelly.
I will go one step farther… if you do not have a vapor barrier on the ground, you should. Plastic sheeting (6mil) is fine for this. Black plastic will help stop plant growth under it (blocks any sunlight that might enter the space), and it too needs to be glued at the seams, where it will be overlapped.
The repairmen will groan or complain when you tell them this, because it is more work, and if not done properly, can be messy. If the home belongs to the park, you may not want to argue with them about it, because it will be their own property that is damaged in the long run… if this is YOUR home, however, then you should insist on it being repaired properly.