Is the siding on your new home properly installed?

Quite frequently during new home inspections (phased inspections or the final inspection) the siding has been found improperly installed.  The installation method is most assured to make it through your closing but how long afterward?  Construction defects are still around regardless of what some builder might assure you of!  Many builders do want to provide you a new home without construction defects but their efforts still fall short and can cost you money in the long run.  One example of this is the poor installation of siding that we see on new homes and the effect that poor installation has down the road on existing homes.  The siding looks real pretty when new and freshly installed but in many cases it is a problem waiting to happen.  In this installment of new home defects we will look at a few of the many issues we find with improperly installed siding.

First let’s start with four general types of siding used on new homes.  We won’t spend much time on the first two types since they are not seen often at all here in our area whether on new homes or replacement on existing homes.  In my opinion and preferences I would not use either of these two sidings for various reasons but most importantly because the better last two siding types are available.  Whether I would be building new or replacing existing siding I would rather have a more reliable and backed siding product than the first two.

The lowest quality product is nothing more than a pressed cardboard or almost pressed paper type of siding.  Although this type of siding is rarely seen these days on new homes it is still in production.  Being nothing more than a pressed paper type product it does require very exacting installation, very frequent inspections, and a considerable amount as well as frequency of maintenance.

Another type of siding we do not see often is Polyvinyl Chloride or PVC siding also typically called vinyl siding.  This siding is the same basic concept material used in the PVC pipes of your home.  PVC siding has come a long way since its original inception with better quality materials and its cost is very low compared to engineered wood or fiber cement siding.  However even in our harsh, hot, and sunny climate I do not feel comfortable with its use on any home I would purchase.  Also with our frequent hail storms (some large hail too!) it is subject to more damage than the engineered wood or fiber cement siding products.

Engineered wood siding

Engineered Wood Siding by Louisiana-Pacific Corporation, LP SmartSide

Another type of siding is an “Engineered Wood” product like this Louisiana -Pacific Corporation SmartSide (LP SmartSide) siding pictured here.  Engineered wood products are very good products that when properly installed will last a very long time and with considerably lower maintenance than the paper type products.  Engineered wood products are made from lumber mill scraps making them environmentally more friendly than much older fully sawn lumber siding.  Engineered wood products, such as this siding, are also typically more economical (cheaper) than their fiber cement composite type sidings both in cost for the product as well as cost of the labor to install them.  But don’t let the cheaper price fool you since they are very good products again when they are properly installed.  There are multiple manufacturers of this type siding but LP is one of the largest and will be used here for descriptions.

The last to mentioned are the typically more expensive but considered to be longest lasting fiber cement siding products.  By and large the most popular and largest manufacturer of this type siding is James Hardie Building Products Inc.  This product uses actual fibers embedded in a cement base.  As a result you can understand how it can be much more resilient to damage not only from lack of basic maintenance but also impact from weather related events.  However it is typically the most expensive option not only in materials cost but the labor needed to install it properly.  Later the repairs as well can be more expensive if needed.

So if the last two are so great how can a builder mes up the installation?  Well that’s very easy to do when the cheapest sub-contractor bids are used and you have a Building Supervisor, and the City Building Inspections Department, not doing their jobs!  These are just several of the significant issues we find with improper siding installation.

Improper fasteners

Trim nails used to fasten interior trim but used on the exterior.

Trim nails used to fasten interior trim but used on the exterior.

Trim nails used to fasten interior trim but used on the exterior.

Trim nails used to fasten interior trim but used on the exterior.








Every siding manufacturer worth their salt will specify the type of fastener to use when installing the siding and trim pieces.  The fastener may be a nail or screw or an option of either.  The manufacturer also specifies where to place the fastener and at what interval along the length and width of the siding product.  With lap siding the most popular method of fastening is called “Blind Nailing”.  That’s where the first siding board is put in place and nailed as directed by the manufacturer along the top edge.  The siding piece above is lapped over the top of this place and also nailed as directed.  As a result the actual nailing is not visible when the siding is completely installed and the top trim board is put in place.  However nailing of the trim boards is many times visible if the nails used have not been fully driven and/or caulked and painted over.

The siding/trim manufacturer typically specifies a full round nail which is a nail that has a full round head.  Some might allow a half-round nail which is one with a semicircular head.  These nails have at a head that can sit flush to the siding or trim piece and hold it in place.  In either case the nails are specified to be corrosion resistant (rust resistant) since even if they are painted over they can still possibly be affected by moisture.  When nails rust they obviously fail but before that they begin to back out which loosens the siding and trim board.

What we see in these two pictures (farther out and close-up) are “T-Head trim nails!  These nails are used for fastening interior trim such as baseboards, or other very light duty trim applications.  They have a “T” shaped head which is completely insufficient for securing a heavier siding or trim board.  They can easily be driven way past the surface of the siding or trim which further reduces their holding power.  On top of that they are not corrosion resistant and were never intended to be since they are an interior use nail.

These nails are destined to fail but they will most likely hold up long enough for you to go to closing on the house.  They may last until after your one year warranty point.  Or as we have seen in some cases they don’t even last before construction is complete.  Also since we can not see the blind nailing pattern (see above) we can not tell if they used trim nails for the actual siding boards.  However chances are very high they did use improper trim nails on the siding as well.  Even though trim nails are very lightweight they will easily penetrate through engineered wood siding and if the nail gun pressure is set high enough, and the trim nails strong enough, they might even be able to penetrate the fiber cement sidings.

Siding and trim not painted

Exposed and unpainted edges

Exposed and unpainted edges

Exposed and unpainted edges

Exposed and unpainted edges








Obviously I am sure nobody has to tell you how important it is to properly paint any wood product that will be exposed to the elements!  After all water damage is highly evident over time.  This is an engineered wood based trim and siding on this house.  Water will wick into the wood, cause paint to peal, rust the fasteners and rot the wood.  With it the trim and siding start detaching.  Every manufacturer of wood based siding does require the field cut ends to be properly primed AND painted.  Primers are not used as water repellent coatings.  Also keep in mind that the actual siding boards are many times cut at their ends to fit and most likely not primed and painted and only covered over with the edge trim pieces.  Many varieties of siding do come pre-primed and even some painted but not ALL come that way.

So what about the fiber cement sidings since after all water does not affect cement does it?  Well even James Hardie requires the field cut ends of their products to at least be primed.  I can’t tell you specifically why but can only expect that is because when cut it does break the edge of the pre-primed/painted surface.  Once broken water can wash at the primer/paint in place and start pealing it away.

Improper installation above roof surfaces

Siding and trim not raised above roof surface

Siding and trim not raised above roof surface

Here we have a common example of siding and siding trim materials almost in contact with the roofing materials (shingles and flashings).  All siding/trim manufacturers require their materials to be raised from 1″ – 2″ above any roofing materials.  The distance is typically 1 1/2″ or more and determined by the manufacturer.  As water runs down the roofing materials it can wash against the bottom edge of the materials and splash up and under it coming into contact with the possibly unprimed and painted back side.  Raising it above the roof surface helps prevent that from happening.

We just mentioned siding and trim not being properly painted and how all manufacturers require field cut edges to be properly primed and/or painted.  The siding and trim here has been angle cut to follow the roof line.  Between the shingles and the siding you can barely see the silver colored metal flashings.  There is no room to get a paint brush or other painting equipment between the shingles and flashings to paint the bottom edges without paint overspray on shingles and flashings.  There is no overspray or paint on either shingles or flashings and you can certainly bet the bottom edge of that siding and trim is most likely not painted.

Not properly sealing the siding to trim joints

Siding to trim joints not sealed.

Siding to trim joints not sealed.

Siding to trim joints not sealed.

Siding to trim joints not sealed.







Time is money to subcontractors and the least amount of work performed is the least amount of time spent and the more money saved, for the subcontractor that is!  Of course the subcontractors time savings will cost you money down the road.  Here we have vertical trim boards lapped over the horizontal siding boards and the vertical joint where they meet is not properly sealed (caulked).  In the left picture, bottom left trim board piece, and the right picture, bottom right trim board piece, both have been cut open (slit) to allow the flashing to pass through and not properly sealed.

For the importance of properly sealing go back to the picture at the beginning of this post for the LP SmartSide siding.  What you see there is the front, primed side of the siding on the left and the rear completely bare wood side on the right.  LP does not require the backside of their siding to be primed and painted as long as it is installed properly which is by caulking these joints to prevent water contact to unprimed and painted surfaces.  Other manufacturers are the same.  Rainwater and other moisture sources WILL make it behind those trim pieces and they are typically also not primed or painted on the back side.  When water makes it behind there it can also migrate back behind the horizontal siding pieces.  That all equals slow water damage from the back side and outward.  You will no doubt make it through closing and possibly longer but time and weather will destroy this siding!

So how is this all allowed to happen?

Poor siding installations are performed quite frequently.  If you want to see the effects a good place to look is above the roof at the chimney chases of homes several years old that have siding on the chase.  Being so high up they are typically the easiest to see but the least maintained.  You’ll see the effects with peeling paint, rotting and detaching trim and siding, etc.  The reasons this happens are simple.

  1. To a subcontractor time is money and properly installing siding takes time.  There are good subcontractors out there but after seeing plenty of poor installations, and the effects of it, there is an apparent shortage of good subcontractors.
  2. Every home building corporation wants to build you a great home.  Unfortunately you can take the home builder with the best record and they are only as good as their Building Supervisors and the Builder’s Third Party Inspection company performing their quality control (QC) inspections.  If the Building Supervisor is not watching the subcontractors work then this will happen.  As for the QC company they are a subcontractor as well and well “Time is money” and if they shortcut their inspections this will happen.
  3. But isn’t the City Building Inspections Department suppose to catch this?  Well yes they should but if you ever watch a City Inspector they are rarely on site for any length of time and typically nowhere near long enough to catch what they should.  The City Building Inspections Department does not have the manpower to spend performing proper inspections and as a result typically accept the Builder’s Third Party QC inspection results as the needed inspections.  Go back to item #2 and you can see just how well that doesn’t work out!
  4. You as a buyer do not hire your own Third Party Inspector to catch these things.  There are hundreds and hundreds of errors a good Third Party Inspector working for you can find and report on.  I can tell you from my experiences I have never performed an inspection without finding errors!  As a buyer you need to decide whether you want to save money on inspections and take a chance errors don’t turn to big problems later or have the inspections, find the errors, and have the builder correct the deficiencies before you take possession of the home.

What is truly sad are how many buyers do not have their own Inspectors looking out for them!  Once you take possession of the home many problems that can occur later, that could have been prevented before, can easily be called “Normal Wear & Tear” by the builder and immediately become your problem to correct later.  For a builder having to deal with call backs for anything is not something they want to spend their money on.


PS Inspection & Property Services LLC is a full service home inspection and light commercial inspection company servicing the entire Dallas and Fort Worth, Texas metroplex as well as all areas around them.  If you are located outside of these areas I can still help service your needs so call to see how.  I strive for the satisfaction of my clients in everything I do.  The services offerings include:

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If you have an inspection need we can customize an inspection for it.  Please visit our main site at PS Inspection & Property Service LLC.

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