Al-Boug and Al-Awtar: What They Are and How They Affect Electrical Rough-In
If you are finishing an apartment or overseeing electrical and plastering work simultaneously, you need to understand al-boug and al-awtar. This is not just a masonry topic — it defines the final wall plane, and an electrician who doesn't account for it creates proud or recessed electrical boxes that only become visible once the painter arrives.
What Is Al-Boug?
Al-boug (plural: bo'ugat) are small cement mortar reference pads placed on the wall before plastering begins. They are typically ~5×5 cm each, spaced roughly 50–60 cm apart horizontally and vertically. Their thickness equals exactly the required base coat (al-betana) plaster thickness — usually between 1.5 and 2.5 cm. The boug pads are the reference ensuring the finished wall is perfectly plumb and flat.
What Are Al-Awtar?
Al-awtar (singular: watar) are vertical strips of cement mortar connecting the boug pads to form guide rails for the plasterer. The craftsman fills the space between awtar with mortar and levels it with a wooden screed (al-gadda) flush with the awtar. The result: a perfectly flat wall surface.
Plastering Stages in Order
Al-Tartasha (Scratch coat)
The first layer — a liquid cement slurry thrown onto the wall to create a rough bonding surface for the base coat. Not levelled, just coverage.
Al-Boug (Reference dots)
Placing the reference pads on the wall after the scratch coat dries. A plumb string or laser level ensures all pads are in the same vertical plane. This is the most critical stage — from it the electrician determines the final wall level.
Al-Awtar (Guide screeds)
Connecting the boug pads with vertical mortar strips. Each watar runs floor to ceiling and its face is levelled flush with the boug pads.
Al-Betana (Base coat)
Filling the space between the awtar with mortar and levelling it with the wooden screed. This is the main plaster layer and forms the bulk of the plaster thickness.
Al-Zahara (Finish coat)
The final smooth layer over the base coat. Gypsum or fine sand, only 2–3 mm thick. Its face is the surface that receives paint.
The Electrician's Relationship with Al-Boug — Why Every Electrician Must Know These Stages
The box (socket or switch housing) depth must account for base coat thickness + finish coat thickness. The face of the electrical box must sit flush with the finished plaster surface — neither proud nor recessed. The rule: set the box so its face sits back from the bare wall by the total plaster thickness.
Typical total plaster thickness in Egypt: scratch coat (5–8mm) + base coat (15–25mm) + finish coat (2–3mm) = total 22–36mm. Average: set your box 25–30mm back from the bare wall. Best practice: wait for the boug to be placed and ask the plasterer for the exact thickness.
Corrugated conduit pipes must be chased into the wall deeply enough to disappear entirely under the plaster. A conduit that protrudes from the bare wall will not be covered by the plaster and will show through after painting. Correct chase depth: conduit diameter + plaster thickness + 5mm tolerance.
For gypsum board (drywall) walls: there is usually no wet plaster, so the wall thickness equals the board thickness itself (12.5–15mm). The box type used is completely different — drywall-specific boxes with expanding anchors are required.
Common Mistakes and How to Avoid Them
Cause: the electrician set the box too shallow, or the plaster ended up thinner than expected. Result: the socket or switch face protrudes beyond the painted wall surface. Fix: during finishing, the box can be pushed deeper if plaster is still fresh, or use an extension frame.
Cause: the electrician set the box too deep, or the plaster ended up thicker than expected. Result: the socket appears sunken into the wall. Fix: use a compensating frame or a box with a deeper faceplate.
Cause: the wall chase was cut too shallow. Result: the conduit creates a raised bump under the plaster visible on the finished wall. Fix: before plastering, inspect all conduit runs and deepen any chase where protrusion is visible.
The biggest mistake: the electrician completes the rough-in and plastering begins without agreeing on plaster thickness. Required: the electrician should be present when the plasterer sets the first boug pads to confirm thickness before finally fixing boxes.
Inspecting Al-Boug as an Owner — What to Check
- Boug pads are plumb and level — use a plumb bob or phone spirit level app to verify
- Spacing between pads is consistent (~50–60 cm) and covers the full wall
- Boug thickness matches the agreed specification in the contract
- No electrical conduits protrude beyond the boug level
- Electrical box faces are approximately at the boug level (or slightly behind)
- Boug was placed after the scratch coat and after electrical conduit installation
FAQ
Can the electrician install sockets and switches before plastering?
No. The electrician installs only conduits and boxes during the rough-in stage. The sockets, switches, and faceplates themselves are installed after plastering and painting are fully complete — installing them before would damage and contaminate them.
What is the difference between al-betana and al-zahara?
Al-betana is the thick base coat (15–25mm) of cement and sand mortar, providing the main body of the plaster and levelling the wall. Al-zahara is the thin final smooth coat (2–3mm) over the base — either gypsum or fine sand — and is the surface painted directly.
What is the correct depth to recess electrical boxes in the wall before plastering?
The rule: the box face must end up flush with the final zahara surface. Since total plaster thickness in Egypt is typically 22–30mm, set the box face back from the bare wall by that same distance. Best practice: wait for the plasterer to set the boug pads and ask directly for the actual thickness.
Should the electrician be present during plastering?
Not throughout, but they must agree with the plasterer on base coat thickness before work begins, and inspect box positions immediately after the boug pads are set — before the base coat starts. An error found at that stage is easy to correct. After the base coat: major complication.
What is the mortar mix ratio for al-boug and al-betana?
Al-boug, awtar, and betana: cement + lime + sand at 1:3:6 for interior walls. For exterior walls: 1:2:5 for increased moisture resistance. Al-zahara: gypsum + fine sand 1:2, or pure gypsum for dry interior rooms.
Is al-boug required on every wall or just the main ones?
Properly, al-boug is required on every plastered surface to guarantee flatness. In very small rooms or narrow corridors, some plasterers use only awtar without full boug pads. From a quality standpoint: full boug on every wall is the correct standard.
What happens if the electrician ignores the plaster thickness and fixes boxes incorrectly?
Three scenarios: if the box is proud — the finish must be broken and redone or an ugly extension frame used. If the box is recessed — an extension frame is needed or it stays sunken permanently. If a conduit protrudes — a visible bump remains on the finished wall. Worst case: demolish and redo the entire plaster — wasted time and money.