Okay, let's break this down, assuming you're talking about electrical conduit for running wiring inside the block wall

The Short Answer (and Important Considerations):

Without specific instructions (engineer's plans, electrical plans, specifications, or architect's instructions), you should generally default to surface mounting the conduit, unless there's a compelling aesthetic or functional reason to recess it, or any applicable code.Here's why, and some more detailed considerations



Lack of Instruction = Flexibility

If the plans don't specify recessed conduit, you're generally free to choose the more efficient and cost-effective method, which is surface mounting.

Surface Mounting Advantages



Quicker and Easier

Significantly faster installation. Less labor cost.

Less Invasive

You're not cutting into the block wall, which can compromise its structural integrity (especially important for load-bearing walls).

Easier Maintenance/Changes

Future access for repairs, additions, or modifications is much simpler.

Lower Material Costs

Surface mounting typically uses less conduit and fittings.

Recessed Mounting Considerations (Why it MIGHT be required/desired)



Aesthetics

Sometimes, a clean, flush look is desired, where the conduit is hidden. This is a purely cosmetic decision.

Protection from Damage

If the wall is in a high-traffic area where the conduit could be easily bumped or damaged, recessing it provides protection.

Space Constraints

In very tight spaces, recessing the conduit might be the only way to fit everything.

Specific Code Requirements

Rare, but sometimes certain electrical codes might dictate recessed conduit in specific situations (e.g., in hazardous locations). This is unlikely in a standard building.

Engineering Requirements

An engineer may have specified recessed conduit for structural reasons (to avoid concentrated loads or to ensure consistent wall thickness).

If you DO recess



Plan Ahead

Accurately measure and cut chases in the block before laying the blocks. This is MUCH easier than trying to chisel out channels later.

Structural Concerns

Avoid deep chases that could weaken the wall. Consult with a structural engineer if you're unsure. Don't cut into rebar or other structural elements.

Backfill Properly

Once the conduit is in place, backfill the chase with mortar or grout designed for block walls. Ensure the backfill is properly compacted to prevent voids.

Cover Plates

Use appropriate cover plates to protect outlets and junction boxes that are recessed in the wall.

RMC vs. EMT



EMT (Electrical Metallic Tubing)

Thin-walled, lighter, and easier to bend and cut. Suitable for most interior applications. Generally less expensive than RMC.

RMC (Rigid Metal Conduit)

Thick-walled, heavy-duty, and offers more physical protection. RMC is more suitable for exterior applications, underground runs, or areas where the conduit is likely to be exposed to physical damage.

Recommendation


Clarify

Before starting the work, try to get clarification from the client, architect, engineer, or whoever commissioned the work. Ask specifically if recessed conduit is required and, if so, why. Document this communication.2.

Code Check

Review the local electrical codes to ensure there are no specific requirements for your application.3.

Default to Surface

If there are no specific requirements, install the conduit on the surface of the wall using EMT (unless there's a reason to use RMC, like outdoor exposure or a high-traffic area).4.

Document Everything

Keep detailed records of your installation, including photos.

Important Disclaimer: I am an AI chatbot and cannot provide professional electrical advice. Always consult with a qualified electrician and ensure your work complies with all applicable codes and regulations.* Flag for review