Modular, Mobile Homes, and 55+ Community Work
Oak Point, Waterview Village, Southmeadow Village, Cranberry Village, Town & Country Estates, Matfield Woods, High Pond Estates, you name them we've worked in these communities.
Modular, Mobile Homes and Trailers are built similar to, but different than your traditional stick built house. And almost all are built out of state and then shipped to Massachusetts.
The problem with this is that many are built to different standards that may or may not meet the codes here in Massachusetts.
Mobile Home Roofs
The biggest issue we have encountered from all our work on mobile homes and trailers, is that the roofing assembly is not installed correctly and does not meet Massachusetts roofing code.
These roofs are low pitch, which require entire coverage of Ice and Water Shield, but what we have found is that almost all have only 3' of Ice and Water Shield if any. Come winter when ice dams form the water backs up and causes significant interior damage.
The below photo is a prime example of what we normally find on these homes. No Ice and Water shield or even paper whatsoever. By code anything between a 2 and 4 pitch, MUST be fully covered with Ice and Water Shield, which you can see in the second photo.
From our experience we have seen many other roofers only install 6' of Ice and Water shield. Either they do not fully understand the building code requirements or more likely trying to save money at your expense as the Ice and Water shield is the most expensive component of any roof job!

Properly Installed Ice & Water Shield
The below roof is a 2.8 pitch, which by code requires full coverage of Ice and Water Shield. Make sure your roof is installed correctly!

Mobile Home Siding
In every instance where we had to remove and replace siding we found that NO underlayment such as Tyvek, which is used as a moisture barrier was ever installed by the manufacturer. (see photo below)

Mobile Home Skylights
Most of the skylights installed by mobile home manufacturers tend to be non-insulated bubble skylights. These are made of a thin polycarbonate plastic, offer no insulation whatsoever, and eventually crack and leak. (see below photo)
Since almost every mobile home roof is low in pitch, a Velux Curb mounted skylight, which lifts the skylight up off the roof deck, is required.
Old Leaky Bubble Skylight
Old Polycarbonate skylight with tar around the perimeter in an effort to stop the leaking.
Velux Curb Mount Skylight

This is a correctly installed Velux Curb Mount skylight. The skylight is physically lifted up off the roof deck using 2x6 framing. It is then sealed with the Velux supplied White Ice and Water shield, which is required for the warranty.
Many roofers fail in using this white Ice and Water shield, and without it, you will NOT be covered by Velux should you ever have a problem.
To finish this install off the supplied Head and Sill Pan with Step Flashing surround the Curb mount and is then shingled.
Sadly we replace improperly installed skylights all the time. This is another major point of failure with most roofers. They are NOT certified and trained by the manufacturer and incorrectly install the wrong skylight for the low roof pitch. As a homeowner you lose. This is why it is so important that your roofer ALSO be a certified Velux installer.
Mobile Home Windows
Most trailers have 2x3 framing instead of the traditional 2x4 framing. One must be aware of this when installing new doors and windows with extension jambs so that they can be installed properly. We must also take into account the weight of Bay windows for example.
In the below photo it shows a trailer with an old Bay window. From the inside you could easily see that due to the weight it had sagged almost 2" from it's original position! The 2x3 framing was insufficient to support a window of such large size.
We removed the old heavy bay and installed a flush mount mulled unit with 2 Double Hung windows and a central Picture Window.