Tuesday, December 17, 2013

Construction Mock-Ups


I had a situation arise last week where an installed construction mock-up conflicted with the construction documents that were approved by the building department. In regards to priority and subordination of the construction documents, the contractor argued one way and the Architect/Owner argued another. The situation was exacerbated by the fact that the contractor did not have a formal set of notes from the mock-up meeting. This begged the question, how can we improve the mock-up process and how does this relate to the hierarchy of construction documents? In this article, I outline the purpose of mock-ups, explain how to conduct a competent mock-up, and demonstrate how all parties can maximize the benefit of mock-ups.


What is a Mock-up?

This may be a refresher or “mock-up”  may a new term. Mock-ups are full-sized models constructed using the exact construction techniques used in the field. Mock-ups are intended to allow the team to study all aspects of the design & assembly. They can be built separately from the structure or can be incorporated into the finished building.

AAMA window spray testing mock-up in project's parking garage

Intent of Mock-ups

The purpose of a mock-up is to help reinforce and define the process, sequence, and quality requirements of complicated components and systems. In my experiences, mock-ups have typically addressed windows and doors. I believe that the owner should require mock-ups for the conditions typically repeated across multiple parts of the building. Mock-ups are very rarely required for “one-off” installations with window installation being a good example. There may be hundreds or thousands of windows to be installed on a project. It behooves all parties to agree on the process and quality standards before commencing with the window installation. When all parties participate in the process of installing the first window, design questions can be handled immediately and the team can therefore identify any missing information needed to properly install windows.

In my opinion, the approved plans and specifications supersede any installed mock-up. The primarily reason for this is the fact that the plans and specifications are the primary instruments used to convey design intent while mock-ups are supplementary. This hierarchy is typically addressed in the construction agreement (Section 1.2.1 in the A201 and Section 7.1 in the A107). Additionally, mock-ups are subordinate to the approved plans because the building department has reviewed the plans while the building department does not review mock-ups. The mock-up is also not intended to replace or supplement the plans.
 
Sample of "butterfly" patch of self-adhered flashing at rough-in of bottom window corner.
Hands used for scale.


Best Practices for Mock-Ups

Depending on your specific role in the mock-up process, there are a number of steps that you can take to improve the quality of the mock-up process. You will also be able to protect your interests with these suggestions. I have divided these best practices by party and role:


Contractor

The contractor should be deliberate as to how he staffs the mock-up process. All of the field superintendents should attend the mock-up installation. The “Supers” are the first line of defense in spotting non-conforming work. Reviewing the mock-up gives the superintendents a chance to see how a “correct” installation looks.

The general contractor should include mock-up dates on the project’s master schedule. Below, I include a very simple example:

 

Mock-ups should also be listed on the 3 Week Look Ahead schedules distributed at the weekly Owner-Architect-Contractor (OAC) meetings. These meetings are a good opportunity for the project team to “touch-base” and ensure that the project is progressing according to plan and to address problems. Again, a simple example is below:

WEEK OF 12/02/13
WEEK OF 12/09/13
WEEK OF 12/16/13
Scheduled Work
· Install traffic coating at lobby.
· Roofing install Phase 2.
· Frame Phase 4 Corridor walls
· Concrete Pour on 12/05 at Level 4 decks.

Administration
· Submit SGD Submittal


Other
· N/A
Scheduled Work
· Install traffic coating at 4th floor.
· Roofing install Phase 3.
· Formwork east side ADA ramp
· Erect scaffold – west side
· Roof drains – Phase 4

Administration
· Product Substitution – Roofing Insulation

Other
· Framing Inspection – Level 2
Scheduled Work
·  Install traffic coating at 4th floor.
·  Roofing install Phase 4.
·  Pre-rock Phase 4.
·  Concrete Pour – East ramp


Administration
·  Receive approved SGD Submittal

Other
·  SGD Mockup starts on 12/18

Subcontractors

These are usually the entity or entities that will perform the actual work. In some cases, such as the windows, there will be many subcontractors involved. The window installer will be responsible for installing the initial self-adhered flashings. The sheet metal subcontractor may be required to install the flashing while another subcontractor would be required to install lath & plaster. Additionally, there may be a waterproofing contractor for the deck coatings. All of these subcontractors should attend the mock-up meeting and be prepared to perform their role.

In the past, I have instructed the general contractor to require that all subcontractors have their foremen install the mock-up. These foremen are going to be the field generals later on when construction is underway. If all of these foremen are shown the expected level of quality, there should be no drop-off in quality once the foremen disperse to lead their individual crews.

Architect or Construction Manager

The Architect/CM should include language in the project manual that requires the contractor to indicate mock-up dates on the master construction schedule. A good Architect/CM will also require the contractor to include dates of when Submittals will be provided. A great Architect will be able to connect the links between submittals and mock-ups. As a general refresher, Submittals are collections of sketches, product info, diagrams, and instructions that are submitted by the contractor for the architect’s review. The intent of Submittals is to help ensure that the correct products are being used on the project. Going back to the schedule, it is important to show these dates so that all parties can anticipate upcoming mock-ups and invite the necessary attendees. This also allows the team to decide upon the location of the mock-ups.

The Architect/CM should also review the first few required mock-ups at the preconstruction meeting. This will get the “ball rolling” on the first few mock-ups and will allow the contractor to begin sourcing products and subcontractors. The preconstruction meeting is also the time when the team should discuss the basic mock-up process.

The Architect, assuming that he/she is responsible for consultant designer coordination, should draft mock-up attendance requirements into the consulting agreements for each designer. This will contractually require the consultant to be in attendance. If your designers are competent, they will see this requirement and will structure their fee accordingly. This is an example of “an ounce of prevention is worth a pound of cure”.

Lastly, the Architect should bring the applicable drawings, specification sections and approved submittals to the mock-up installation meetings. The submittal-approved products should be compared to the products provided for the mock-up. You should photograph these items to verify whether the products match or conflict.

Ownership Entity

The Owner should add language in Architect’s contract that requires the Architect to develop a list of required mock-ups. This should happen early in the design process as the Architect should know the “usual suspects” of beneficial mock-ups. It would also help the owner to maintain his own list based on previous projects. This list of mock-ups should also identify the parties, trades, and manufacturer’s representatives that should be in attendance.

The Owner should include this list of required mock-ups as an exhibit to the construction contract with the general contractor. This will contractually require the contractor to install the mock-ups. Just as with consultants, expect this to affect the contract price of the work –but only slightly.

Photographs

I cannot stress this enough, take lots of photographs! Photograph the packaging of products, photograph the people who are in attendance, photograph each step of the installation process. Take notes of each step of a process and photograph the note as a reminder prompt before you photograph each step. Please see these previous articles that I have written on site photography:
 
Application of caulking to window nailing flange.
Photo clearly identifies Dow 795 caulking.

Taking Notes

Regardless of your role, take notes as to who was in attendance and what issues were discussed. You will need your notes to refute false claims by others if they are issuing meeting minutes from the mock-up meetings.

Mock-Up Meeting Notes

Remember the golden rule of meetings, if there is a meeting there should be notes published afterwards. Below if a list of things that the minutes should address:
1.    Mock-up intent
2.    Date & time of mock-up
3.    Attendees
4.    Weather & temperature during mock-up
5.    Applicable submittals and specification sections
6.    Applicable details and sheet #s
7.    Restate that the mock-ups do not supersede the approved plans and specifications.
8.    Location of building where mock-up is located (or off-site mock-up)
9.    Decisions made during mock-up
10. Photographs
11. Detailed listing of the process of installation
a.    Vital for door and window installation & flashing.
12. Follow-up action items & deliverables
a.    Who does what by when

Conclusion

Mock-ups can be a great tool for all project participants. It is difficult to conduct the process in a thorough and detailed manner. As with most tasks, the more practice you get with mock-ups, the easier they become. Take some time now before your next project and develop a process that you will follow. Your future self will thank you.

Additional Reading