How to Look

at a House


A blog with answers
to your questions about
HOME INSPECTION
and HOME MAINTENANCE


More Blog Posts on Similar Subjects:

  1. I’m buying a ‘50s house with a “gravel” roof. Is the roof going to be a problem.

  2. When is a railing required for the edge of a deck or porch?

  3. What’s the difference between “composite” and regular wood siding?

  4. Should I buy a fixer-upper?

  5. Should I be suspicious about a concrete block house covered with siding?

  6. How can I tell if a house has insulation?

  7. What do you look for when you inspect a roof?

  8. What are the most common problems with older houses?

  9. Why does my insurance company want a roof letter?

  10. I saw some staining on the ceiling. Do you think the roof is okay?

  11. We are smarter than water!

  12. Why is there mold around the air conditioning ducts?

  13. What do you look for when inspecting vinyl siding?

  14. What should I look for when buying a “flipper” house?

  15. Why are there score line grooves in the concrete floor of the garage?

  16. Why does my concrete floor slab sweat and get slippery?

  17. What is the average lifespan of a house?

  18. Should I refinish-resurface my pool with paint or plaster?

  19. What are the common problems of different types of house foundations?

  20. What are the common problems to look for when buying a 1970’s house?

  21. What is the average life expectancy of stucco?

  22. What is the average lifespan of plywood siding?

  23. What is a “continuous load path”?

  24. What should I do about a tree with roots running under my house?

  25. What are the warning signs of a sinkhole?

  26. What are the pros and cons of aluminum siding?

  27. Why does the laminate wood floor move when I walk across it?

  28. What causes paint to peel prematurely on the exterior of a house?

Welcome to our blog!
We want you to be an informed homebuyer, and each blog post is a question that we have answered for our friends and customers over the years. Hope they help you make a good choice for your next home.

  1. 3)Distance from bottom of joists to ground - A deck that is close to the ground can be visually pleasing, but it will have a short life. Moisture is constantly rising out of the soil, and a deck built just above the grade lacks adequate ventilation to disperse the moist air created. When a deck is sitting on or just above the ground, you can expect that the lifespan will be cut in half; and, in some cases, the joists will rot as fast as the deck boards above them.
       The deck in the photo below is an example, built close to ground and in an advanced state of deterioration. As you look at the image, it’s easy to visualize how each joist creates a separate compartment of unventilated wetness.

  2. 4)Type of foundation - The best deck foundation is stable—with a real concrete foundation, not precast deck blocks sitting in the dirt— and has no wood in contact with the ground. But, if you do end up installing wood posts in the ground, be sure they are marked as rated for “ground contact”—which means there is more preservative in the wood—and put the uncut end into the dirt. The pressure-treatment of the wood applied at the factory does not saturate completely to the center and, when you cut off the end, the exposed core of the post will have little or no chemical treatment to resist rot.

  3. 5)Water traps - “Water trap” is a term that construction professionals use to designate any surface of a wood structure that is exposed to the weather and does not slope adequately enough to drain off any water after a rain. Examples of a water trap in a deck would a board that has cupping (concave at top surface), a loose knot, or checking cracks—all of which will allow puddling of water that accelerates wood rot in the area. Deck boards with any cupping  should be installed with cupped face downward, and any boards with loose knots or checks rejected, or the bad section cut away when possible.
       Also, if the top of a wood post is cut off perfectly level, standing water will soak into the end-grain of the wood and center pocket of rot will begin within a few summer seasons. Cutting the tops of posts at a slant or in a pyramid shape is better, but even then the end grain is still susceptible to rot as shown in the photo below. The best solution is installing a waterproof decorative post cap.

  4. 6)Construction Details - A ledger board, where the deck meets the house, is the most common source of failure in a poorly built deck. A good builder uses spacers to create a gap between the ledger and the wall to let rainwater flow down the wall behind the board, and avoid rot from water trapped against the wall. But a ledger should never be attached to the wall a manufactured home, since they are not designed to accept any additional loads. Decks adjoining mobile homes should be freestanding.
       Also, the fasteners used to construct the deck must be rated for use with the specific material, whether it is pressure-treated or composite wood. If regular screws and nails are used, they will have a shorter life than the boards. To read about other details to make a deck stronger, safer and last longer, go to our blog post “What are the warning signs of a dangerous deck?”

  5. 7)Coating - A water-repellant wood coating with an oil or wax base keeps water from penetrating the wood surface. The fungal organisms that cause wood rot need water to survive, so a deck coating applied every couple of years keeps the wood rot at bay, at least for a while.

   Why don’t wood decks last as long as other residential structures? The simple reason is that everything else has a roof over it. Deck boards are exposed directly to the sun and rain, year after year. It’s amazing that they last as long as they do when they are well constructed and maintained.

  To understand the basis, potential use, and limitations of lifespan ratings, see our blog post “How accurate are the average lifespan ratings of home components? Are they actually useful?”


While we hope you find this series of articles about home inspection helpful, they should not be considered an alternative to an actual home inspection by a local inspector. Also, construction standards vary in different parts of the country and it is possible that important issues related to your area may not be covered here.
©2015 - McGarry and Madsen Inspection. -

 

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