Site Visit 10-27-08

10/27/08
7:45 am

40 degrees

overcast & windy

View at entry looking south-east.

Fireproofing installed at gymnasium (1st floor to roof). Framing installation at south complete, framing in progress at north. Roof drain installation in progress at gymnasium and second floor north. Fire extenguishers installed around first floor. Temporary protection of steel structure at roof east and south.

Retaining wall at south-east (adjacent to mechanical room) - installation complete. A Hydro-hi-tech raising scaffold.

In talking with one of Construction Management staff I learned about site safety and weather planning. I asked about the effect of cold weather on working - there were weather reports that called for snow flurries. I was told the snow flurries wouldn't impact the schedule this week because it was not very severe. But the schedule includes a couple of days this time of year to account for inclement weather. The only work affected by the extreme cold is the exterior stone cladding work. Even that is slowed by much. The water for the mortar mix can be heated and the work can proceed. I was also told that eventually they may have to provide temporary enclosures for the work, to which I asked if the extenguishers were a part of that plan. I was then informed that the extenguishers were an Occupational Safety and Health Act (OSHA) regulation.

I got to watch a worker drill through the second floor slab at the south-west. What the photo does not show, and what I learned by watching and talking to the guy, is that he set up a tarp below to catch the steel decking as it fell through and protect the material being stored below.

This is my first attempt to link a video to the blog. This is a short clip of a worker installing a metal stud track on concrete (taken 10/20/08). With a little more editing I was able to add an annotation in YouTube which updated immediately.

Site Visit 10/20/08

10/20/08
7:53 am
30 degrees
mostly clear - slight breeze

Masonry being installed at east wall. Framing at south mostly complete. Fire-proofing installed at first floor (south, east, gymnasium north, east, & south). Roof drains installed at gymnasium roof deck.

There was this architectural/ephemeral moment that stood out. Light coming in from the east through the gymnasium was falling on the cross bracing which was being cast onto the metal studs framing the corridor. It will probably be gone next week, but it creates a striking moment.

Retaining wall at south (progressed to 10- or 12-foot height). Looks like gravel fill with geo-tech fabric and drain pipe. In the framed electrical room within the mechanical room I noticed raised slabs where the electrical equipment is going to be installed. Junction boxes were installed - I think they run locate these first and then run the conduit to and from it (I'd never seen it at this stage). Pipe fitters were hanging pipe at the underside of the gymnasium roof (running along the west wall from south to north).

I took a quick note of all the crews and general work activities. I noticed:
(1) worker on clean-up (clearing standing water from 2nd floor slab)
(2) Carpernters at first floor installing studs + (1) lift
(2) Electricians at mechanical room installing conduit at east wall
(1) Carpenters at first floor north
(2) Pipefitters at first floor east + (1) lift
(2) Pipefitters at welding station set-up at first floor south-east
(4) masons at mechanical room east wall
(4) masons at low south-north wall + (1) lift to transport mortar
(2) masons to mix mortar + (1) mixer
(1-2) mechanical sub(s) + (1) lift

At this stage there seemed to be quite a few lifts in operation and with the studs being installed space is getting more defined and thus more constrained or restrictive.
Another thing I noticed is a notation around the west and north side of the building indicated offsets. There was a triangle with a center hole drilled in it and the notation 2' o/s to 5.5 (meaning there is a 2' offset, from column 5.5).

Site Visit 10/13/08

10/13/08
7:55 am
45 degrees
clear

The weather is getting noticebly colder. Concrete poured at column-slab connection to conceal steel base plates. Metal stud installation has begun at the first floor south-east (above the mechanical room). Fire proofing has been installed at the first floor south and west wings. Control joints have been cut in all concrete slabs. The gymnasium has a depressed slab - to receive the future wood flooring. Z clips have been installed around the perimeter of the first floor at second floor framing.

This looked to me like a custom-made piece. Mostly assembled from flat and stock pieces of steel.






The 1-1/2 metal channels were being stored at the gymnasium, in the mechanical room I noticed the installed metal studs had the 1-1/2 inch metal channel running through them at about 6-feet above the finished floor. The studs were almost 20-foot tall - I think to give extra bracing without using a cross-brace.

Retaining wall construction has begun at the south wall - just west of the entry to the mechanical room. This area is going to hold the electrical equipment. A trench has been excavated from the mechanical room to the future location of the electrical equipment. Block is being stored in front of the wall (Trad Ash Gray from Dillon & Co.).

View at south-east corner of site looking north-west. Water proofing installed around perimeter of mechanical room, drilling in progress through wall. Before I left I saw a delivery of steel piping for the pipe fitters (marking on the side of the pipes: ASTM A53B ASME SA53B 5LB 6IN. x 0.280 IN x 21 ft HT NO 195287 China). Also the scaffolding leading from the first to second and roof levels has been wrapped in plastic. Is this to protect from the elements? Why not wrap the entire building in a temporary protector from the elements? Has this been tried before and if so, to what effect?

Site visit 10/06/08

monday 10/06/08
7:45 am
45 degrees
clear skies
Cold morning. "Small" activities on site, meaning very little heavy equipment use.

One man + one fork lift (with extentible boom) were removing the curring paper at the gymnasium slab. Keeping track of time, I noticed he was able to remove about 1/4 of the paper in about 45 minutes (should be done by lunch).

At the North-east of the site stone masons were cutting and placing stone for a low wall. 2 foremen and 8 workers (of the 8 workers; 4 were cutters & 4 were laborers).

At the South-east corner some excavation was taking place outside of the mechanical room. 1 excavator + 1 small loader+ 1 laborer. At one point the operator of the loader signalled the operator of the excavator and the excavator proceed to use the bucket to push the excavated soil into the loaders bucket.



Inside the mechanical room 3 electricians were installing conduit (1 in a extinding platform + 2 apprentices bending pipe). The photo of the electrical piping running next to the core-drilled holes for vertical pipe revealed the sequencing and coordination required between the pipe-fitters and the electricians. First the pipefitters bore the holes throught the slab and deck, next the electricians run their conduit, and then the pipefitters will return to run the vertical piping (meanwhile, carpenters have set up walls in the mechanical room). Two carpenters (1 master carpenter + 1 apprentice) were installing the metal stud partitions dividing the spaces. A plastic tarp was hung on the wall at the north - possibly to protect from fireproofing which was being installed above at the first floor. The corner north of the mechanical room has been backfilled with earth and graded to a level that the stone-masons can now work safely.

The fireproofing crew of 4 seemed to comprise of 1 foreman and 3 labores. The equipment being used was 1 professional mixer + 1 pump + homemade quickset mixer. The professional mixer was being loaded with Cafco 300 (http://www.isolatek.com/Product_Search.asp?ProductId=1) ready-mix spray on fireproofing.

The location for the generator pad at the south-east of the building has been marked (see photo). Pipe fitters above the mechanical room appeared to be core-drilling the slab. A single worker was making his way around the site distributing trash bins and plastic bags. Z-clips appear to have been installed at the underside of first floor girders at the north section of the building.

The curred slabs appeared to be maintained as broom clean, no debris or mud was visible. The last area of the first floor to receive a concrete slab will be the intersection between the west side of the building (entrance hall) and the south side (toilets, lockers, etc.).

Next on-site visit planned for 10/13.

Site Visit 10/03/08

friday 10/03/08
7:45 am
40 degrees
clear skies

This morning I walked around the outside of the site and got a good idea of some changes that have taken place since my last visit on (09/24/08). There were only two workers visible on-site. They were over at the SE corner above the mechanical room - possibly pipefitters who had moved their equipment to that area a couple weeks ago. Some PVC piping has been delivered and is being stored at the west of the site. The pipe appears to have varrying diameters and a constant length of about 20 feet.

The installation of the concrete slabs seems to be complete. The first pour was in the SE corner above the mechanical room (on 09/15/08). Subsequent pours were on the South side, West side first and second floor, and main gymnasium space. The Concrete at the South and West (1st & 2nd) is unprotected so I assume it has curred to sufficient strength. The slab at the gymnasium was covered in a brown paper to retain moisture and, as observed this morning, was kept moist by a couple of standad lawn sprinklers.

At the south-east corner of the site, water-proofing has been installed and formwork that had been installed at the perimeter of the first floor has been removed. The red-iron appears to have been coated with intumescent paint (note the white color of the steel columns, girders, and cross-bracing). Also at the south-east corner the site entry gate has been moved southward about 30-40 feet.

The entry has large crushed stone and a concrete culvert close to where it meets the service road.
Some questions were raised during this observation: Did the entry gate and work road have to be relocated? Could the future roadways serve as temporary site roadways, thus reducing the amount of site work required to change from working roads to finished paved surfaces? In observing the workers a week ago during the gate relocation a crew of about 4 workers was involved in relocating the entry and regrading the roadway. Assuming that task took a minimum of 1-2 days, the overlap of the site access road with the future driveway may have shaved a couple of days off of the sitework (small amount over the course of the project but a reduction non-the-less).

At the North of the site the steel structure for the gymnasium is complete (there was one girder at the north-east of the gymnasium which had not be installed because of trenching equipment which needed to be removed). The structural steel is completed and the metal decking for the roof appears to be installed. I cannot seem to grasp how the decisions for painting certain columns, girders, and braces are made (perhaps it has to do with the construction type?). At the north-east corner some stone was being installed around a low wall. Additional stone was stored between the wall and the constuction manager's trailer. As I said earlier, hardly any visible activity on site today.

More posts to follow - Monday I resume a regular schedule of on-site observations.
And a reminder larger views of all photos posted at the upper-right hand corner of the blog can be accessed by clicking.

The PVC pipe case

This is a PVC heater. It does exactly what it says it does, it heats PVC. The amazing part is what the PVC is like once it is heated. I observed two workers heating an 10-foot length of pipe in order to join two pipes which were offest from one another. When they took the PVC out of the heater it looked like a big strand of spaghetti. It was flopping around all over the place. When I asked one of the workers, he explained that the PVC remains pliable for about five minutes.

So why do we even need a tool like the PVC heater? (This is where the goal of the blog takes root). In discussing the situation with the worker he explained that the drawings indicated all the piping to be run closely together through a concrete wall. If he were to follow the drawings, he would have to bore through the concrete wall, or space the pipe in such a way, that it would interfere with the rebar, thus jeapodizing the integrity of the foundation system.
To get around this he spaced the pipe connections accordingly so that they missed the rebar within the foundation wall formwork before the concrete was poured. This forethought by the specialty contractor maintained the integrity of the wall, but did it add time and cost to his part of the work?

This brings up another subject I am currently learning about in school. Knowledge Management. This involves the recording of events, such as the one described, so that some can later access it and learn from it. For example, if this piping event had been cataloged by the specialty contractor, s/he would be prepared for the next time he saw it on a set of drawings; if the construction manager cataloged it, s/he would be prepared to account for the added time and cost for additional piping and labor; if the designers (architect, electrical and structural engineer) were made aware of the situation, they could account for it by developing a protocol for drawings and ensure that this conflict would be accounted for in the drawings, leading to it being accounted for by the construction manager and specialty contractor.

As I said, I am only just learning about the structure of knowledge management, but it is something my brother and I have been discussing the past couple of years in regard to Architecture offices. We would both come accross mistakes or events that cause delays in production, questions durring bidding, and errors in the field. If ther ewre some way that these observation could be captured, logged, and accesssed, these small errors and ommisions could allow for smoother operations down the road. The challenge is creating the structure in the company, incentivizing honest appraisal and developing a system that is easy to access, revise, and use.

The PVC case may be a small incident that only added a days worth of work to the specialty contractor, but that specialty contractor may have had to readjust his schedule for the week. Take that one incident and multiply it be all the speciality contractors and all the small design decisions that lead to field changes, and there may be a week or more that could be shaved off a job if steps are taken to observe and proactively seek solutions to problems and ensure they don't recure in the future. [Quite a bit of writing, but this has been brewing for the last couple of weeks]