BCT 144 Structural Analysis Assignment

Setting

The joys of owning a dishwasher. The ease, simplicity and time saved by stuffing all of our dishes away in this little cube. This little, unassuming cube... that sprang a leak. Under our floor. For what may have been weeks. One morning I am taking dishes out of our sink, and putting them into the dishwasher for a cleaning, when I realize suddenly, the floor is spongy under my feet. Squishing even, literally like a sponge and when I get down for an alarmed, close inspection the smell. Musty, like a wet basement. I rip open all of the cupboards underneath the sink and counter, looking for the culprit, sure that the sink has sprung a leak. But I can't find the source. And then I look to my left, eyeing the dishwasher. I pull it out. Sure enough, damp wet and newly molding laminate confirms that the dishwasher is the offender. 

Structural Issue

Now, our landlord came over promptly and removed the dishwasher, ripped up all of the laminate flooring in the area and brought in blowers and dehumidifiers to dry the space out. The underlayment was ruined, this thin particle board that absorbed a significant amount of moisture and swelled, pushing the laminate tongue and groove out of place, buckling and cupping.

Cupping Floorboards 

Floorboards spreading apart, due to the underlayment swelling

Photo taken underneath, from the crawlspace. I'm not sure what the purpose of the foam was, but this torn opening is the only place it exists in. I believe my landlord opened this space to see what damage the water had done, and then put this foam in place to hold the insulation in... You can see residual water damage on the foam itself - although this could be from exposure to the crawlspace, but that would also expose the insulation, and floor system to the moisture present in the crawlspace during the summer months, resulting in... mold and water damage...

Exaggerated example of laminate flooring cupping. Much easier to see with the level and tape for reference.

The underlayment was never removed. What further damage was done beneath it still remains a mystery. The possibilities are:

• Mold and Mildew are growing in our living space.
• The sub floor may have been damaged, warped or had it's structural integrity ruined.
• The floor joists themselves may have been exposed to water, allowing them to rot and putting everyone who walks on that part of the floor in danger, if they happen to give way.

I believe this is a structural issue because the flooring, sub floor and entire floor system (in this area of the house) may have had it's ability to support the amount of load it was originally designed to hold damaged by water and, subsequently, rot. (IRC R501.2) Sub flooring that has had it's integrity damaged may not be able to support the loads required of it originally (IRC Table R503.2.1(1)).

Work proposal

Ignorance is never bliss. Living in a house with unknown conditions is a recipe for accidents and a multitude of other issues. At the very least, an inspection of the sub floor and joists should be done. Depending on what this inspection reveals, the sub flooring and, possibly, some of the floor joists may need to be replaced (along with parts of the floor system that are already visibly damaged - the laminate flooring and sub floor underlayment.)

For this project I would need the following tools:

• Wonder bar or larger pry bar
• Tape measure 
• Hammer
• Speed square
• Level
• Circular saw or Skilsaw
• Impact Driver and Drill
• Pencil
• Safety glasses
• Dust mask
• Sawzall
• Flashlight/Work light
• 16d Nails

Step 1: Pull up the laminate flooring and underlayment

Step 2: Identify where the water damage extends to in the sub floor

Step 3: Cut out and remove whole sheets that contain ANY water damage

Step 4: Inspect underlying joists

Step 5: If joists also need to be replaced, install them next to the rotten joists

Step 6: Cut out rotten joists and dispose of them

Step 7: Install new sub floor sheets

Step 8: Install new underlayment

Step 9: Install usable laminate flooring and new laminate flooring

Although this repair would most likely only take up to a day to complete, the work being done should be completed while there are no other occupants in the house - there may be negative impacts to occupants. The mold/fungi spores that may be released into the air during deconstruction/construction may be harmful to all individuals. A HEPA filter should be used while the project takes place and I would be wearing a dust/mold mask. The area will need to be sanitized thoroughly after the project is completed. Also, other hazards to occupants exist: There will be an opening in the floor through which individuals may fall. There may be enough debris over which someone could trip.

Material Estimate

Item	Description	Qty	Unit Measurement	Unit Cost	Extended Cost
Flooring	Laminate 8mm, Oak Brown	72	sq ft	$1.69	$121.68
Underlayment	100 sq ft roll Serenity Foam	1	100 sqft roll	$14.97	$14.97
Subfloor	Advantech OSB 3/4"	3	32 sq ft sheets	$16.28	$48.84
2x8x8 Floor Joist	No.2 Pine 8'	9	8 foot board	$5.96	$53.64
16d Nails	Steel Sinker 3 1/2"	1	5 lb bucket	$9.87	$9.87
Total					$249.00

Labor Estimate

# of Days	# of Workers	Total Man hours	Rate per Hour	Total Labor
1	1	8	$20.00	$160.00*
Project Total				$409.00

Conclusion

I believe that the total cost of this project is perfectly reasonable. When weighing the possible cons associated with the health risks of living with mold, and having the unknown possibility of the floor system collapsing under us, $409.00 is far cheaper than any hospital bill. I feel comfortable doing this project myself, it is straightforward enough, does not require any special equipment and can be done in a day. As a beginning carpenter, it could even be the perfect first project.

* Labor cost would be negligible if the repairs were performed by myself. True cost of the project would therefor be $249.00.