Roadmap of DBS Inspections For A Detached Garage Conversion

Each project has its own unique conditions, so this list may not be applicable to all projects universally. However, it will provide a general idea and understanding of the inspection sequence on an ADU or a single-family residence.

1. Pre-inspection.

During this step, the homeowner (if owner-builder) or general contractor will go over all logistical aspects of the project with the city inspector. This is a good time to ask the inspector any questions to better understand his expectations, clarify any code-related points, and make a good first impression.

If converting an existing structure to an ADU inspector will expect to have footings exposed. Alternatively, homeowner or contractor can drill through the footings to determine their depth. If a footing is missing or it smaller than 12 inches, it will need to be reinforced and poured.

This step is important to get to know your local inspector, understand his expectations, and come up with a roadmap for construction.

2. Underground Plumbing Inspection

Once trenching and sewer connection are complete, the plumbing contractor will need to do a pressure test of the system. This is done to verify that pipes are not leaking. He will have vent pipes stubbed out by then too, which will need to get plugged up for the test. A city inspection should be scheduled during that time for the inspector to witness that installation is complete and to sign off on the building card. He will also verify that clean outs, P-traps, and, applicable to some locations, grey-water accommodations are made.

3. Foundation Rebar, Anchor Bolts, And Layout Inspection

Each project will have its own structural elements that need to get installed. Some of them may be a system of multiple spread footings (also called underpins), continuous footing on one side of a garage, or a brand new slab with footings along the perimeter. Inspector will need to ensure that rebar and anchor installation complies with stamped structural plans. He will verify distance between soil and rebar (needs to be at least 3 inches), layout of structural elements, sleeves/ wrap around plumbing lines, and rebar splice length before signing off on the inspection card.

In the case of missing footing and/ or anchor bolts, a deputy inspection will need to be called prior to the city inspection to verify proper installation of rebar and/ or anchor bolts. Deputy inspection report will then be provided to the city inspector.

After inspector's approval you will be able to pour the required structural elements.

Figure 1. Excavated Footings With Rebar And Anchor Bolts Laid Out For Spread Footings.

Figure 2. Excavated Missing Footing With Doweled-In Rebar. Regard Installed.

4. Vapor Barrier Inspection

In most instances architects will specify Redgard as a vapor barrier of choice. Make sure your contractor follows all application instructions to achieve the highest effectiveness. It goes against the manual to apply Redgard on freshly poured concrete. It is recommended you let concrete dry for a few days.

Figure . Regard Complete, Rebar Installation for Topping Slab Ongoing.

5. Roof Sheathing Inspection

As you complete interior framing and get started on MEP rough-in, the next step will be to get the roof inspected. Typically, you will have several penetrations going through the roof - plumbing vents, HVAC vent pipes, in some cases skylights. You may want to route all mechanical ducts like kitchen range, dryer, and bathroom fans through side walls to minimize chances of potential water intrusion.

Inspector will come out to inspect your nailing pattern, completeness of sheathing coverage of the roof, and will give a green light to install roof on the structure.

Once your exterior wall framing is done, windows and exterior door is installed, it is time to start closing your building envelope. At this stage building paper and lath (if stucco is your finish) or weather barrier (for siding) will need to start getting installed before inspector gives their approval to install insulation.

6. Rough MEP Inspection

You may want to wait for mechanical, electrical, and plumbing trades to get inspected simultaneously to save inspector some traveling time. Here are the expectations for each of the trades that your local inspector will want to see:

Mechanical

• Ducts are supported and strapped

• Indoor air handler has a switch

• Condenser unit has a switch

• Caulking/ spray foam is complete around all penetrations to the exterior

Electrical

• Electrical boxes are properly made up, labelling recommended, and attached to brackets/ studs

• No loose wiring. All wires should be attached to framing members by means of staples

• Wires are landed on the panel or terminated outside

• In-stud penetrations are sealed with spray foam (recommended)

• Inspector may selectively check fire certifications on light boxes

• Electrical boxes in fire rated walls must have fireproof padding around them. All penetrations in a rated wall must be sealed with fire caulking.

Plumbing

• Interior pipes are insulated

• Exterior pipes are secured to structure

• Inspector will check clearances and dimensions around laundry traps and sediment traps (in gas lines)

• All drain lines have vents

Figure . MEP Rough In Ongoing.

7. Building Envelope Inspection

Building envelope will need to get installed before you can proceed with insulation. If you are applying stucco as you finish, inspector will want to verify that building paper is lapped properly. He will inspect the stapling of lath to paper to ensure a tight attachment. It is recommended that sealant is applied over areas where staples penetrate the paper to provide better protection from moisture.

If siding is selected as finish, building will need to get wrapped with a Weather Resistant Barrier (WRB) like Tyvek. Inspector will need to verify proper treatment at seams and overall integrity of the barrier.

At this time inspector will want to make sure that your openings are properly waterproofed with sheet metal or tape flashing and verify that all of your fenestration matches requirements of Title 24. Make sure to not remove windows stickers before this inspection. Otherwise, you will need to present an order confirmation that outlines physical characteristics of each opening with solar heat gain (SHG) coefficient and the U-factor.

Figure . New Building Paper and Lath Integrated Into Old Layers,

Staples Treated With Sealant.

8. Insulation Inspection

Once the inspector gives green light to cover walls after passing of the MEP inspections, you may proceed with insulation of exterior walls, ceilings, and partition walls. You may be allowed to install shear walls without getting a separate inspection for insulation, but that is up to the inspector. When insulating, make sure you get the right R values for each area - per Title 24, walls need to be at R-15, ceilings - R-30. We recommend that you or your contractor take a closer look to make sure that as much area as possible is covered with insulation to avoid thermal bridging and heat loss in the future.

Figure . Fully Insulated Structure.

9. Shear Wall Inspection

Depending on the nailing pattern of your shear walls, deputy inspection may or may not be required. Typically, anything less than or equal to 4'' on center for boundary and edge nailing will require a deputy report. 1/2'' thick plywood is most commonly used for shear walls in ADUs. You contractor will need to use shims in areas without shear walls to make sure that drywall is flush everywhere.

Next up you will want to get your drywall screw pattern and shower pan inspected to kick off the next major stage of your project.

Figure . Installed Interior Shear Walls.

10. Drywall Screw Inspection

You may call in for drywall screw inspection once you close up all the walls. If you hire a professional drywall installer, this will be the fastest inspection of your entire project. Inspector will need to verify screw spacing, which should be 7 inches on center. After inspector's approval you can proceed with fire taping and mud application.

Figure . Installed Drywall With Taped Seams.

11. Shower Pan Inspection

Shower pan, in majority of cases is waterproofed using the hot mop method (keep in mind that some drain manufacturers will void their warranty if hot asphalt is applied for waterproofing purposes). Alternatively, some people elect to install a liner. Regardless of the installation method, the pan will need to get inspected to ensure that it can hold water and drain properly. Before inspector arrives, make sure to fill up the pan with water, 2 inches below the top of the curb. You may plug up the drain with special inflatable plugs or a regular water-filled balloon. Inspector will verify that the pan holds water and has adequate slope to drain all of the water out.

Figure . Fresh Hot Mop Application for A Neo Angle Shower.

12. Shower Wall Inspection

Depending on your tile contractor, there are two possible options when it comes to shower wall installation and waterproofing. Option 1 - installation of backer board with mesh and a waterproofing compound over screws and seams (typically Regard or Hydroban). Option 2 - similar to stucco installation - building paper, with lath and two coats of cement mortar.

Once your inspector verifies the integrity of your system, he will give approval to start tile installation.

Figure . Hardiebacker Waterproofing With Redgard. Tile

Installation Ongoing. Orange Sheet in The Picture - Anti-Crack

Ditra Membrane By Schluter.

13. HERS Test

HERS stands for Home Energy Rating System. You may be required to have it done at your property in accordance with Title 24 requirements. Check pages that contain all Title 24 specifications in your approved set of plans to confirm which of your systems need to get tested. This testing method will need to be performed by a 3rd party agency. The purpose of the test is to evaluate how energy-efficient your home is based on air leakage, water heater performance, performance of your HVAC appliances, and indoor air quality. Keep in mind that will not have to have all of those parameters evaluated. You will need to present results of this test to your city inspector before they can issue a certificate of occupancy.

14. Clearances from Department of Public Works, Recreation and Parks

Typically clearances from those entities are easily obtained. ADUs are not subject to fees from Recreation and Parks. Similarly, the footprint of the ADU is too small for the fee to be assessed. In order to obtain those clearances, all you need to do is email respective agencies your request and within a few business days they will be reflected as "Ok for C of O" on the LADBS portal.

14. Final Inspections

Miscellaneous Inspections

Based on your electrical set up, you may need to engage LADWP to provide you a meter spot, which entails them coming onsite to determine the best location for a new meter. Typically this is done when you want the ADU to be metered separately, if you are planning to have an individual meter for the EV charger or if you are upgrading your meter and LADWP finds any of your clearances from other utilities insufficient.

We hope that you find this article helpful in any of your endeavors. If you are looking to get more of your questions answered, please contact us on the number listed on the Home page.