Installing new vinyl siding over old wood siding.
Can you do this? Yes, it can be done. But there are criteria that should be paid attention to.
There are always criteria!
This newly sided house looked good from the street. When I got around back I found that the new vinyl had been installed over old wood siding.
If what you can see doesn't look good, what you can't see can be a real bother!
I see damaged wood siding.
Is that inappropriate?
Not necessarily, but what are the "criteria" that should be met before vinyl siding can be installed over wood?
1. Obviously the old wood siding should be in good shape. It should not be rotten anywhere, loose, or damaged. Any bad stuff should be replaced.
The problem I have with what I see here, and this is the only place I could see wood siding underneath, is that the wood looks damaged. Was the new vinyl similarly installed over rotting wood? Loose seams? Bulging wood siding? I DON'T KNOW, I CAN'T SEE IT.
2. Vinyl siding likes a firm, flat surface onto which it is installed. Gaps in the wood beneath would not be good. Any trim around windows and doors should have been removed. Uniformity is important under vinyl siding. Vinyl siding is not nailed onto a house, the nails are left protruding from the surface and the vinyl virtually hangs in place. Bulging underneath, or looseness underneath, can affect the vinly siding's ability to stay together in place and be less weather and wind resistant. The problem I have with what I see here, and this is the only place I could see wood siding underneath, is that the wood looks damaged. Was the new vinyl siding installed over loose wood? There was bulging on the vinyl siding - was that because of the wood siding underneath?
3. Vinyl siding must be installed over a moisture-resistant barrier. Any of the modern wraps would be appropriate. Moisture wraps need proper installation that includes attachment and the taping of seams. The problem I have with what I see here, and this is the only place I could see wood siding underneath, is that the wood looks old, and installed before moisture wraps were common. Tar papers could be used, but prying up the wood siding I could see nothing underneath. And looking into a couple of seams in the vinyl siding I could see no moisture wrap.
4. Windows and doors should have a proper flashing prior to the vinyl installation. The problem I have with what I see here, and this is the only place I could see wood siding underneath, is that I could not tell because I could not see it!
My recommendation: when some things look wrong it is hard to assume that the rest of everything was done right. New vinyl siding touted as a "feature" in the listing information is only a feature if it is done properly, if not professionally. And if you can't tell that from what you can see, what you can't see is very worrisome indeed! An invoice from a professional, well-known company is the best way to proclaim something as a feature.
Jay Markanich Real Estate Inspections, LLC 
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560
Oh yes, that looks like it's probably a recipe for disaster. It's most likely worse i the areas you can't see. Expensive mistake for the seller.
Who knows Debbie. Things like this are almost always sold to people who overlook such stuff!
Good morning Jay. Although the standards require a moisture barrier, it's not required in this area. I have seen some real terrible installation jobs. I think they must've worked as a butcher in a meat market. – LOL
Required or not, Michael, Mother Nature will enforce her codes rigorously and with impudence!
Good morning, Jay Markanich every local siding company I know will refuse to install vinyl over old siding of any kind.... they strip the house...
Likely so Barbara! Key words: siding company.
This is pretty common around here.
Jay, we see this all the time in this area. It's a quick cover-up "fix" for a home that is looking sad. Unfortunately, someone down the road is going to inherit a problem.
Ahhh, the ol lipstick on a pig routine!
Greg - my son has a house in Wrightsville Beach. I have seen that it's common there myself!
Mike - a historic home in Manassas resided with vinyl and the city made them tear it down!
I'm sorry Fred, but I did not know lipstick was made out of vinyl.
Oh, I see what you mean now.
Or did to begin with.
You'll never know, will you?
Jay- Fred Hernden said what I was thinking. It reinforces what I suggest all of the time... make sure you have a really good home inspector!
Hi Jay Markanich, Thanks for the very informative blog post. It is important to know how to do this and I'm sure like me, most people wouldn't know how to do this properly.
Kathy - it was lipstick, indeed, but expensive then they sprayed stuff on the deck and got it over a lot of the siding in the rear. There was sooo much more to see at this house too!
Sybil - THAT is why Flippers are so troublesome! What they do they often don't do properly.
And someone who doesn't know any better and probably cannot afford to properly fix the problem buys this problem house. A couple of years later once they realize the magnitude of the problem they walk away from the house and it goes into foreclosure. Let's hope nobody buys this property.
Stephen - the guy who does is the one who thinks home inspections are a waste of money. I've met them!
Like most humans Jay Markanich you can't cover up ROTTEN and make it go away
Dat true Deanna! And I have uncovered a lot of rotten humans.