Do I invite the wolf in—or try to keep him out?

Do I invite the wolf in—or try to keep him out?

Everyone knows the story of the three pigs. From that story, we learned that we should all build our houses out of brick if we are to keep the wolfs at bay.

disintegrating brick columnOur houses have to deal with all kinds of wolfs. There are water-wolves, earthquake-wolves, tornado-wolves, wind-wolves and the dreaded lightening-wolves.

No matter what we build our houses out of, they all need to be maintained or the wolf WILL get in.

This house wasbuilt in 1902 and I discovered, much to my buyers chagrin, that the wolf was having his way with the brick foundation. Those pesky mortar-wolves were patiently eating away at the foundation. Almost anything after 116 years would likely show deterioration and certainly all three of the pigs are dead by now regardless of their choice of building materials. The brick foundation has done its job quite well considering the number of significant wolf-quakes it has stood up to.

But now it is likely beyond repair—or at least extensive repairs that would amount to a new foundation will be necessary. The mortar joints and bricks are crumbling and some beams are no longer supported at all.

Unsupported beam and collapsed brick

Unsupported beam and failed brick

Unsupported beam and failed brick

Unsupported beam and failed brick

Someone will have to make a decision as to whether to let the wolves have it—or to try and keep them at bay for a few more years.

By Charles Buell, Real Estate Inspections in Seattle

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Is the foundation bolted or only sort of bolted?

In my many years as a builder–and in my more recent incarnation as a Seattle Home Inspector–something that I have noticed about houses is that they can be very forgiving structurally.  Complete structural failure of a component is sometimes difficult to arrange.  Other times, with the requisite conditions, we will see the weekend warrior’s deck go all kattywampus in the back yard–with the beer keg rolling down the street as the ambulance pulls into the driveway.bolting1How does the house know which rules to break and which ones not to break?Take foundation bolting for example.  It is a question I get asked often–is the house bolted to the foundation?  Sometimes it is the client that is concerned, sometimes it is their insurance carrier that wants to know.Over the course my building career I have seen foundation bolting go from ½” bolts, 6-8 feet apart, with no washers under the nuts, to 5/8” bolts, every four feet, with 2” square-plate washers under the nuts.  In addition to this bolting are all manner of seismic strapping and hold-down bracketss with bolts as big as 1-1/8” in diameter.  And this is in residential construction–commercial construction is even more extensive.All of this is fine and dandy and will likely help your house do very well in seismic activity up to a 7 or a little higher on the Richter scale.  After that, all bets are off supposedly–but still the amount of damage would have to be somewhat less.

Again I ask, “How does the house know which rules to break and which ones not to break?”

A while back, I inspected a house that was over 30 years old.  Its age tells me that it has been through at least two fairly major earthquakes in this region–including the 2001 Nisqually Quake.  The house had no visible damage and yet the foundation bolting–while present–looked like the following picture.

 bolting2

This bolting is almost worse than no bolting at all–as the sill plates are nearly completely severed every 6 feet.

So the insurance company wants to know if the house is bolted.  Any inspector would be “nuts” to say that this foundation is “bolted” wouldn’t they?  And yet the house is doing fine after 30 years and is “standing the test of time.”

The house has broken the “rules” and is doing fine.  Keeping houses on their foundations is not restricted to, or dependent on, code requirements for bolting.  There are many older homes in Seattle that are not bolted to their foundations at all and have little or no seismic damage going back to earthquakes even stronger than any this house wiggled through.

For example there was a method of pouring foundations in this area, that used to be very common, where the bottom plate of the wall was put right in the forms so that when the concrete was poured it actually came up higher on the plate all the way around the inside of the foundation.  This created an installation where the wood walls were naturally locked in place laterally by the concrete wall itself.

bolting3The reason this 30 year old house has done so well is because of the many “steps” in the foundation.  Stepping the foundation aids in interlocking the foundation and wood walls, thus restricting movement laterally.  If we take the same house with a uniform foundation–with no steps–and did the same type of bolting as in the second picture, the house would likely not fare as well.

As you can see, answering the seemingly simple question of whether the foundation is bolted or not does not really provide much in the way real information to anyone.

How the house is performing in relation to its age and methods of bolting is much more useful information to provide.

Brand new homes, with no “history” represent other challenges in terms of how we discuss foundation bolting.

Certainly any reporting of foundation bolting is going to have to come with some “qualifiers.”

 

By Charles Buell, Real Estate Inspections in Seattle

 

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Of tree stumps, rocks and prayers.

 

Your house foundation.

It is what holds your house nice and level and keeps it from sliding down driveway and out into the street.

Foundations in new construction are designed for the slope of the land, as well as soil conditions, numbers of stories and other factors.   Not long ago I inspected a home where, way back around 1900, four trees had been cut off on the site and these cut-off trees became the four corner supports for the home.  In the following picture one can see one of the tree stumps that is now surrounded with “additional” foundation that has been added over the years.

Stump foundation

Stump foundation

Yes it was very small and was most likely nothing more than a get-away cabin that was built before the area became overrun by “progress.” 

A tree is a relatively good analogy as to how foundations work.  We have the support post (the trunk of the tree) and the footing (the roots that spread the load out over a bigger area).  Any tree, when impacted by forces it was not “designed” to deal with, can become uprooted and the tree will topple over.  The footing of trees is pretty much designed to secure the tree in place and counter the forces placed upon it by wind.  A bunch of trees together will do more to help each individual tree than any lone tree can do.

A house foundation is similar.  If it is supported by four corner supports and we loose just one of the supports bad things are likely to happen to the furniture, and occupants—never mind the structure itself.  Now if we divide the spaces so we now have 8 supports, we go from catastrophic failure to something in between “catastrophe” and “sloped-floors”—-commonly referred to as “character.”  If we divide those spaces again, we now have supports at 16 points and it becomes even less likely that loss of one of the supports is going to be as problematic.  Of course this is all relative to the distance between the supports and the type and size of beams spanning those supports.

Obviously if we fill all the spaces between the supports we have what we call a continuous foundation and some of that foundation could be effectively taken away without much consequence to the whole house.  If one thinks about a foundation in this manner, it makes it easier to understand how inconsequential some cracks can be.  Of course one still needs to be able to interpret the cracks—-because they could mean something more.

We still have a fair number of post & pier type foundations around the NW that were built around the turn of the century—-the 20th century.  They almost always have inadequate supports even though the spacing of the support posts would likely be adequate by current standards.  What was usually NOT adequate however was the size of the footings under the support posts.  Lots of times these posts were simply placed on large stones—-including both stones found on site as well as cut blocks of stone brought to the site.  Sometimes they were merely set on blocks of wood—-or as previously stated—tree stumps.

Rock pier support

Rock pier support

These houses almost always have “excessive character” that would not be tolerated in any other type of construction.  The best solution almost always involves either replacing the support post footings with ones engineered for the soil conditions (always considerably bigger than the ones originally used) or install an actual full foundation under the home.

These post & pier homes can be very difficult types of houses to “fix.”  Fixing usually involves making a decision about whether one can live with the amount of sloping of the floors or not.  If one cannot, and the house is to be leveled, factoring replacement of all the lath and plaster throughout the home will become a necessity as opposed to staying a cosmetic “feature” of the home.  This gets really complicated if the house has undergone interior work to counteract some of the settlement.  Floors that had been leveled to compensate for the sloping may now become out of level.  Windows and doors installed level and plum will now no longer be level and plum.

Most people opt for simply “stabilizing” the home with proper supports and/or foundation and bank on retaining the cosmetic “features” and “character” of the home.

At a recent inspection all or most of the support footings had been “upgraded” at some point in the past—maybe 50 years ago.  Because these footings were undersized, being impacted by roof water making the ground around the supports soggy and located so that the post was not centered above them the house has continued to settle and is about to play tiddlywinks with the footings.

Failed pier support

Failed pier support

These supports will need to be re-done or a new foundation poured under the house—-they did not succeed in stabilizing the house at all with this repair.

By Charles Buell, Real Estate Inspections in Seattle

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