CABIN 1.8: CRAWL SPACE EXCAVATION - PHASE 2

With the primary excavation completed it is now time to take control of the crawl space.  What does that mean?

It means getting control of the structure, the building systems (sanitary sewer) water supply, air movement (ducting) and framing of new and existing openings for crawl access.

The first priority was the structure.

Beam at left to be replaced

It helps to have a friend like Duane to assist

New Beam and columns.

The floor beam below the joists that was buried in the dirt was found by the architect to be deficient.  It had been an on-going snack for carpenter ants.  Replacing the beam required new footings for columns, temporary shoring of the existing floor, jacking up the floor to relieve the load of the joists on the beam. a new beam and columns.

Once the prep was done, the beam took about an hour to replace.

The beam that was replaced

The picture above illustrates the condition of the beam we removed and replaced.

The next effort took place beneath the main area of the cabin.  New concrete footings were set in place to receive new columns to support the existing 4 x 6 beams that were resting on some concrete block and a strategically placed stack of field stones as the supports.

The existing beam was reinforced with two 2 x 6's with 1/2" threaded rod through bolts at approximately 24" oc, a new treated 4x4 column with side supports glued and bolted to specifically support the new beams.

Column and beam reinforcement

The existing beam was reinforced with two 2 x 6's with 1/2" threaded rod through bolts at approximately 24" oc, a new treated 4x4 column with side supports glued and bolted to specifically support the new beams.

While we jacked up the floor to relieve pressure on the existing beam we also had the opportunity to adjust the level of the floor which is now more level than when we originally acquired the structure.

Just the addition of the one column mad a huge difference in the solid feel or bounce (deflection) of the floor.  It is really solid.

One more column needs to be installed to complete the task.

The photo above is the finished column to beam connection below the guest room floor.

With this phase of the structural work done it was time to move on to the plumbing and sanitary waste line - that will be the next blog entry.

CABIN 1.7: CRAWL SPACE EXCAVATION - PHASE 2

Once the framing was removed from the floors in North portion of the cabin, and the beam was reinforced with some additional bearing capacity we were ready to complete the excavation.  

The strategy was to complete the excavation in approximately five (5) hours with a four man crew.  I ended up being the fifth individual on the crew.  Three were digging and putting the excavated dirt in buckets.  I was taking the dirt and moving it to the wheelbarrow outside and one person was on wheelbarrow duty.  With five people we were able to move a lot of dirt.

The dirt was really hard requiring an electric jackhammer with both a spike and spade attachment.  The assault on the crawl excavation was also complemented by the traditional shovel and pick arsenal.

Excavated crawl space

The excavated area was sized to address two important criteria:

1.  Maintain the structural bearing slopes of the existing foundations; and,

2.  Provide access to the perimeter of the structure for the installation of new heating ducts, 

      perimeter insulation and utilities

The photo above shows the condition of all the existing framing prior to structural work that was done for the floor framing.

This view shows the excavated area which exposed the cast iron sanitary sewer lines, galvanized water supply lines. amd shows the floor beam that was buried in the ground that was damaged by carpenter ants. 

Next Post:  structural re-construction and re-inforcing.

CABIN 1.6: CRAWL SPACE EXCAVATION - PHASE 2

The phase 2 excavation of the crawl occurred after the floor sheathing was removed from both the bedroom, bathroom and closet.  The important part of this work at the bathroom was to expose the galvanized water piping and old cast-iron sanitary sewer piping that was under the floor joists and not accessible prior to this.  So...if there was a leak in the existing piping it would either be undiscovered for a while (and one of those leaks was discovered) and / or if repair was required the flooring would have to be removed until the piping was discovered.  And there were signs that the floor in these areas had been previously removed to access piping issues.

FLOORING REMOVED AT BATHROOM

TUB REMOVED - PLUMBING EXPOSED

The  floor sheathing was removed throughout the areas at this part of the structure including the closet area.  This gave a clear idea of the condition of the existing framing.  There was generally good news after being able to review and observe the entire state of framing.  Even though the original framing was essentially laid directly on the ground there initially appeared to be minimal issues such as wood rot or other damage.

I found a beam that had been buried in the ground to support the floor joists.  In the closet area - which is at a corner that collects water on the exterior - the framing appeared initially to be dry and in reasonable condition.  The dirt just past the beam appeared damp and after digging around appeared to be damp due to a leak in one of the galvanized water supply lines.  That line was cut and capped and the dirt dried up.  Without removing the floor and going through this exercise, that leak would have continued and ultimately would have been a problem that may not have been discovered for quite a while.

I then removed a series of floor joists to provide access for the final excavation effort.  

After opening this area up I was able to do an additional effort to look at and inspect the foundation and found that the vertical joints on the West wall had not been grouted with mortar. So, after exposing the exterior side of the foundation and mixing a bag of mortar I pointed the vertical joints with new mortar to seal the foundation.

With some additional support installed at the beam supporting the joists we were ready to complete the crawl space excavation.

CABIN 1.5: CRAWL SPACE EXCAVATION PHASE 2

It has been a while since posting on the construction efforts that have been underway on the cabin.  Since the last post there has been a lot of work done and I'm going to attempt to catch up over the next week or so.

When last I wrote I had laid out the rationale for the excavation of the crawl space.  The last post photo shows the floor still in place.  The floor needed to be removed in order to complete the crawl excavation process.

Exposed Original Floor Construction

Unexcavated Crawl Under Bedroom Area

The first phase of the excavation indicated the original construction of the floor at the addition was built directly on the ground.  Clearly done before building codes or building permits in the Town of Eagle.

Upon removing the floor sheathing this hypothesis was confirmed.

In order to complete the crawl access strategy we ascertained that digging down from the top would be the most efficient methodology.  This was - in fact - the case.

As I uncovered the space I found an intrusion of tree roots from the Chinese elms outside the cabin.  Unruly, large, and seemingly owning the area under the floor, the fight was on.  

Crawl Excavation - Initial Phase

Tree Roots Revealed

The first phase of the excavation was done by yours truly.  One Saturday and part of Sunday I removed 125 buckets of dirt from under the joists.  I calculated this to be approximately 3+ yards of dirt.  As sore as I was I figured I would be a candidate for Tommy Johns surgery...that was a lot of dirt to lift and move.  

You might note in the photo above to the left we used some pretty basic techniques - a red radio flyer wagon was employed to haul two buckets at a time to the wheelbarrow outside which then transferred the dirt to the pile.  One wheelbarrow took four buckets, so I moved about 32 wheelbarrows of dirt - initially.

The tree roots are visible above.   They were removed with a hatchet and saws and are drying out by the firepit for this fall's firepit enjoyment.

At the end of this phase, the photo above shows the state of the guest quarters.  The dirt was removed from below the joists to a depth of 16 -20" and the existing condition of the framing was able to be inspected.  This allowed for an inspection of the inside face of the foundation, and began the process of getting control of the area below the cabin.

CABIN 1.4: CRAWL SPACE STRATEGY

 In the last post I noted the excavation of the crawl space had begun.

The reason:  get control of the space below the cabin so all systems can be accessed from below which includes valves, water lines, electrical and communications.

Why is this important?  One of the reasons revealed itself as I was removing the floor sheathing in the bedroom:  damp soil.  The damp soil indicated a leak of some sort that needed to be fixed.  

So, how do you fix a busted pipe if you don't have access to an 80 year old galvanized pipe with a leak in it? You can either dig a new crawl space or you cut the floor out to access the pipe - assuming you have the ability to know you have a pipe leak.

BEDROOM FLOOR W/ SHEATHING

There are several building code requirements that address this situation:
1.  Access to a crawl space; 
2.  Access areas for equipment and the servicing of that equipment; and
3.  Common sense.

The photo above shows the existing floor with a doorway on the right side of the picture.  There are no access points to get to the crawl space.  With water and waste piping at the area under the door and wall at this area, and no access, one will cut the floor up to repair plumbing.

SHEATHING REMOVED

In this photo, the sheathing has been removed.
     1    Damp soil was found under the wall and near the door (plumbing leak of some sort)
     2    Dirt is up to the joists (fortunately the dirt is very dry)

This is a lot of work.  Some would ask if it is worth it.  In my professional opinion, the answer is yes.  

I will be able to add additional structure to the shower area to stiffen the floor for a new tile shower.  I will have access to the underside of the floor to address systems issues.  I will be able to install a new air distribution system that will not cut through joists to get heat deeper into the space in appropriate locations.  I'll get dirt away from the joists.  I'll be able to condition the crawl space with heated air avoiding foundation ventilation systems that introduce cold winter air that could affect water pipes, ie: freezing them - a less than optimal situation.

By digging this space out I will also be able to introduce perimeter insulation to thermally improve the space.  I'll also have room to install a vapor barrier to the space.

Since this is an 80 year old structure I will also be able to observe the framing and determine if any remedial work needs to be done in order to preserve the integrity of the structure.

The reasons for creating this excavated area far outweigh not doing the work - in my opinion.

So, the work continues.  We are close to completing the removal of the sheathing and the ability to complete the crawl space work.

CABIN 1.3

I have been radio silent for a while; primarily due to an enormous amount of work required to price out a new residence for construction, and because some serious infrastructure work is  being and has been done on the cabin.

There has been key structural work being done - will address in a future post - and the focus of this post:  The Crawl Space.

I am a systems guy.  By that I mean I want access to building systems whether commercial or in this case a residential structure.  I want to be able to access plumbing, heating, electrical and the structure without crawling on my belly to do so.  I want to organize and access water valves, electrical connections and any other control points for the building.  Additionally I want to be able to get to the foundation to install insulation to tighten the thermal properties of the foundation element of the building envelope - install new ductwork and visually observe these systems once installed.

In this little cabin there was a crawl space - but not big enough.  In order to bring the new water line in to the cabin I needed to expose the existing ancient galvanized supply line and expose the area in the crawl space to which the new line would come in from the street.

We are fortunate in that the existing sewer line will be abandoned.  We are going to connect to a new city line that will be brought into the NW corner of the site.  From there it will be run into the cabin on the North side to intercept the existing waste lines.  Right now there is no way to access these lines without serious demolition (which we are doing) so we don't have to do this again.

With dirt not far from the bottom of the existing joists - like within inches - this condition required mitigation.

So...with all the above being considered we have excavated a portion of the crawl space.  The dirt was hard and required a jack hammer to assist.  

The first assault was a one day effort that got about four feet into the crawl with two people and myself as the wheelbarrow  operator.  This first round was done with picks, shovels, no jackhammer.  It was dirty.

Crawl Excavation in Process

We then realized it was necessary to prepare a more intense excavation assault to effectively gain on getting control of the space.  A jackhammer, concrete saw and a four man crew for two days took care of the main area, and penetrated into the space under the bathroom / guest quarters.  The dirt was broken up, placed in 5-gallon buckets and hoisted out of the crawl space and moved by wheel barrow to the current point on site.

Excavated Crawl Space Dirt

Because the dirt was so close to the floor joists in the bedroom area a second effort will be required.  The strategy for that effort includes removing the floor sheathing in the bedroom / bath area and executing the completion of the excavation from above.  This will be more cost-effective and will allow for a complete discovery of existing conditions that may need to be addressed.

Those discoveries will be addressed in a coming post.

RESIDENCE 1.1

Spring is here and construction season is upon us.  The winter season - and darned cold it was - is slowly being moved out of the way for warmer construction weather.  The garage was re-organized this weekend in preparation for structural work in the cabin and then work on the residence.

The winter was spent designing and studying a residence concept for construction on the site.

So here is where we are.  The concept for the residence has become developed to the point where pricing is being executed for the construction.  We have looked at multiple options for the design and structure.  The photo below illustrates the model I built to study massing and siting options and one roof option we looked at for a single level 1600 SF option.  

EARLY DESIGN OPTION - RESIDENCE

The first pricing study that was done was for modular construction under the assumption it would be reasonably cost effective and craning in the modules would save a lot of construction time.  A concept was developed that met modular widths, heights and shipping concepts.  It was sent out and the pricing returned was surprisingly high.  The concept was rather small - approximately 1700 SF with a second level space for a studio and possible guest room.

The second study was for a single level straw bale wall construction.  I did not get into detailed pricing, and did create a design for straw bale walls and construction.  I sent the concept to a Colorado straw bale company that has done really good work and came recommended to me.  That concept, too, came back a little higher in cost than I was looking for.  I did get really good information from the company - Solarwise, Salida, CO - and appreciate their candor and input.  

As an interesting side I was doing technical research on straw bale construction and uncovered several articles that indicated thermal testing on straw bale wall indicating the thermal performance of the walls is lower in actual performance.  The anticipated R-value of straw bales was approximately R-45 and the actual tested performance level in several articles was R-21 to R-25.  This particular fact got me wondering about other options - particularly SIPS (Structurally Insulated Panels) construction.

The equivalent R-value for the 10" SIPS wall panels we are looking at is R-37 to R-39.  

As I write this we are pricing a SIPS panel building - walls and roof.  When constructed, and sealed correctly the envelope will be very tight and efficient.  I have sent the envelope package out for pricing and the panel package has come back favorably.  That pricing element has to be added to the other pricing line items, so the entire cost is not yet known.  I am encouraged.  I realize other pricing elements are still required to develop a complete cost picture...never-the-less we move forward.

On a side note I have installed two data loggers on the site: one interior and one exterior.  These devices are inexpensive tools to help accurately measure temperature and humidity climatic data.  The graph images from the loggers for the interior and exterior are noted below:

The upper graph is the exterior climatic log and the lower graph the interior log.  For a currently uninsulated structure the cabin performed reasonably evenly.  The upper (exterior log) indicates the temperature swings we would anticipate from November to December here in Colorado.

I found a the humidity line at the graph to be the most interesting.  The humidity at the graph was a lot higher than I expected.  The swings in humidity at the exterior were interesting also.  The exterior graph shows the humidity at 60% when the temperature was down to 20 degrees and humidity at  +/- 15% at a 60 degree temperature.  Similar performance is illustrated on the indoor graph.

Colorado is known for its dry climate.  I would not be surprised for increased humidity in the evening (thus frost on our car windows in the morning).  The degree of upswing in the humidity was a surprise. Upon further discussions with various folks it turns out that a lower temperature has a tendency to increase humidity which is reinforced by the performance indicated at the exterior graph.  

In addition to the climatic data I am studying heat gain / loss, solar gain, shading options, window performance, ventilation options, efficient heating and natural ventilation strategies toward a final construction solution.

More to come.