Exterior Coverings-Vinyl Siding

Let’s talk a little bit about vinyl siding. Even if you only install single section manufactured homes, there are still some vinyl siding considerations that you should know.

Creative! But not acceptable!

We can start with how to make a repair to damaged vinyl siding. Maybe the corner post had a close encounter with a telephone pole, or maybe the first course got scraped across a guide rail. The repair is simple! Remove the damaged section of siding and replace it with a new piece!  No, you can’t cut the nailing flange off of another corner post and slip it over-top of the damaged one. And NO, you can’t snap a

I wouldn’t want this on my home!

little piece over-top a hole or other defect or even use caulking to fill a hole. Damaged or defective vinyl siding must be replaced!


Probably the biggest mistake installers make is when they fasten the skirting starter channel to the home. There are two factors to remember when installing the skirting channel: 1. The siding has to be able to freely expand and contract with changes in temperature. 2. There must be no way for water to get between the siding and skirting channels.

I am beginning to see a lot of different approaches regarding the skirting attachment. Some good, some not so good. The recommended approach is to hang the skirting from a separate nailer that is attached to the floor of the home. Most installation instructions tell you to screw a 2 X 4 under the home to fasten skirting. Not easy to do!

OSB sheathing extends below siding for skirting attachment.

Typical in every installation manual

I have seen a few manufacturers extend the OSB wall sheathing below the first course of siding for skirting attachment. Several installers have told me that water seeps into the joint between the siding and skirting. To prevent this water infiltration, I suggest a simple “Z” shaped flashing, slipped under the siding and over the skirting channel to take care of that!

Bottom lap cut off.

Never cut off the bottom lap of siding to install skirting! I have seen this more than I care to admit. It is never a good idea.

Tie Down Eng. Skirt Hang-R

A new device is available that is definitely worth a look. Tie Down Engineering has come up with the “Skirt Hang R” that screws to the bottom of the floor joist for attachment of the skirting channel.

For sectional homes or other home designs that rely on the installer to finish the vinyl siding, there are several other things to consider.

Always remember that vinyl siding is NOT fastened to the home, it is “hung” from the home to allow for lateral movement. Do NOT drive the nails or staples tight against the material. Hang It Loose! Speaking of nails or staples, make sure they are corrosive resistant! Galvanized or aluminum nails and galvanized staples. If the home is new, the manufacturer will provide these fasteners with the ship loose material.

Generally, the siding should be secured at a maximum of 24” on center. Often the siding running under windows and doors will need to be secured by being snapped into under-sill or finish or utility trim using lugs you crimp into the siding. I know that many manufacturers don’t provide under-sill trim….but I think they should! 

Notches needed at top & bottom!

You should overlap siding joints between 1” and 1 ½”. A little extra overlap on hot days, a little less on cold days. Speaking of overlaps, if you have to cut off the factory cut edge, make sure you cut the notches at both the top and bottom of the siding to assure the siding can expand without restriction.

And as always, never just take my word for it. Check the instructions on the siding box and the manufacturers installation instructions!

Expanded Installation Checklist

Those of you who have attended any of my training courses over the past several years, know that I am a big fan of using checklists to document the proper installation of manufactured homes.

The Manufactured Housing Improvement Act requires that installers of new manufactured homes maintain records for at least 3 years. However, they don’t tell you what these records should look like. At a minimum, I have suggested installers use the “Complete Installation Checklist” (found toward the back of every manufacturers installation manual) as the basis for their record keeping.

I contend the checklist should be the most important tool for installers to not only use as a defense in the event of a legal proceeding, but to also help reduce the chance of call backs due to some little problem that may have been overlooked. It is just good business

But to be honest, the checklists provided in the installation manuals are pretty weak (see the example on the left).  So, I came up with a checklist that would hopefully function better for installers and become a more useful tool. It is attached to the bottom of this post for your use (both a word document and PDF). This checklist captures all of the items from the checklist provided in the manuals, and includes some important elements that are left out.   But here is what I think is the best part, the attached checklist can be customized.

You can download this checklist and make your own edits that will specifically work for you. Maybe you want to split it up and assign specific responsibilities to certain people. Maybe you want a checklist limited to single section homes. Maybe you want to make it specific for a particular anchoring system. The choices are yours.

Keep in mind, no checklist (including this one) can every cover every aspect of the installation process. But, I do believe that this goes further than what is currently available. As always, make sure you refer to the home manufacturer installation instructions for proper installation methods

So, have at it! Share comments should you see anything you think is in error or missing!  But most importantly, start keeping records and use some type of checklist!

Expanded Manufactured Housing Installers Checklist

Expanded Manufactured Housing Installers Checklist PDF

Exterior Coverings-Roofing

Shingles blew off due to improper fastening.

Now that Fall is here, I thought it might be the right time to start talking about roofing and siding on manufactured homes. If you check the Manufactured Home Construction & Safety Standards (3280.307) you won’t find a lot of detail. Basically, we need to use corrosive resistant fasteners (shipped from the factory for new homes) to attach an exterior covering that must prevent infiltration of air, water and vermin. 

Bottom line, the code requires that we install the exterior coverings to the product installation instructions. So, it is smart to read the shingle bundle  wrapper, the siding box, or the little instructional insert found in other products.

Let’s take a closer look at some of these roofing and siding products, starting at the top. Roofing! I am going to try and focus on issues that installers are faced with, and what I most commonly see in the field in regards to roofing:

1.       Shingles damaged by the factory installed wind deflectors.

I know you have seen furring strips nailed to the roof with so many nails or staples you can barely get a pry bar underneath to pull them free! Inevitably, the shingles get damaged trying to pull the strips off. And what do you do about the holes left behind from all of those nails? Here is the kicker, when a shingle is damaged, it should be replaced. There is no approved method in any of the installation manuals I have seen that show how to repair a shingle. If your manufacturer is shooting way too many nails in these strips, take some pictures and send them to the QC manager! And ask for a design for proper repair!

2.       High fasteners that prevent shingles from sealing together and allow wind under the tabs.

If the nail head or staple crown prevents proper sealing because it is not driven flush, the shingle can blow off or the fastener can even cut through the tab.

3.       Over-driven fasteners are just as bad! A nail head or staple crown that cuts into the shingle will surely lead to shingle flying off on windy days.

Hinged roof shingles not laying flat.

4.       Hinged roof shingles not lying flat.  You can’t assume that the shingles will lay down over time. The manufacturers rely on you for feedback on how the hinged part of the roof knits together. So, make sure you report any problems back to them!

Drip edge not projects past shingles.

5.       Drip edge projecting past the shingles. This is a problem when the installer has to install the last few feet of drip edge to reach the peak of the roof or along a hinged area. If you can’t slip the drip edge under the shingles so that there is at least ¼” of shingle past the drip edge, you need to report it to the manufacturer. Don’t cut the drip edge to go around a rogue nail or staple.

The other issue that I think we should look at is ice dam protection. To protect the eaves of the roof from water infiltration due to ice damming, manufactured homes produced for cold climates are provided with a type of ice and water shield. The Asphalt Roofing Manufacturers Association (ARMA) says that in areas where the average January temperature is 25° of less, ice dam protection is needed.  I typically see manufacturers use either a self-adhesive product, or they use a multi-layer application of roofing paper that is roof cemented to the roof decking and covered with a second layer of the same paper cemented to the first.

In both cases, the ice dam protection extends from the edge of the roof deck to a point 24” past the interior wall finish of the exterior wall. Should you be called upon to repair any damaged roofing along the eaves of the home, make certain you are provided the needed designs to properly correct the ice and water shield.

How Improper roof ventilation causes ice build-up.

The roof insulation blocking the vented soffit, could result in ice damming!

Generally the top reason an ice dam forms along the eaves of any home is due to improper roof ventilation! The HUD code requires that there be a 1” air space under the roof decking to eliminate cold spots that would lead to freezing of any water running down the roof. Should you have a home with ice dam issues, report it to the manufacturer and ask them to check the roof insulation!

Ok…next time we will talk a little about vinyl siding!