Flat roof waterproofing in Morocco: how to get it right and what it costs

By Yassine AT-TARASSI, architect · Updated on 24/10/2026 · Reference texts (6)

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Most Moroccan buildings have a flat roof terrace, and it takes all the rain and all the sun. Poor waterproofing shows up after the first winter, on the top-floor ceiling. This guide, written for overseas Moroccans, foreign owners, developers and facility owners, explains how the work is built, what the architect checks and what it costs according to the CITURBAREA cost simulator.

Disclaimer: published costs are indicative outputs of the CITURBAREA estimator (October 2026 version), not binding quotations, technical designs or compliance certificates. Apartment buildings and public-use facilities require project-specific drawings, specialist studies, applicable regulations and contractor quotations.

What does flat roof waterproofing consist of?

Waterproofing (étanchéité) is not just "a coat of tar". It is a build-up of layers laid in a set order, from the slab outwards. The chosen system, and its data sheet, sets the type and number of layers:

1. The deck: reinforced concrete slab or hollow-block floor, dry, clean, with no sharp edges.
2. The screed to falls (forme de pente): a mortar of varying thickness that drains water to the outlets. Without falls, water ponds and finds the smallest defect.
3. Vapour barrier and thermal insulation, where specified: extruded (XPS) or expanded (EPS, called PSE in Morocco) polystyrene boards, as the system requires.
4. The membrane: in Morocco the usual choice is a two-layer SBS bitumen system (a 3 mm sheet then a 4 mm sheet, torch-welded). Single-layer, synthetic and liquid-applied systems also exist.
5. Upstands (relevés): the membrane is turned up the parapets, pipes and thresholds, then protected at the top.
6. Protection: screed on geotextile or gravel (heavy protection), paving or tiles on an accessible terrace, or a self-protected membrane.

How much does roof waterproofing cost per m² in 2026?

Installed contractor prices excluding VAT, Kénitra, with the simulator's low-high range in brackets. Prices including VAT add 20%.

Method note: CITURBAREA simulator, version 2026-10, run on 23/10/2026; contractor selling prices excluding VAT in Kénitra (regional factor 0.93), supply and installation; incl. VAT = excl. VAT × 1.20. Membranes and boards: retail prices recorded in October 2026, presumed to include VAT and converted; labour times are engine assumptions calibrated on market installed prices. Rounded to the nearest 5 MAD.

Rounding: amounts excluding and including VAT and quantities are each shown after rounding, so the product of the visible values may differ from the total by a few dirhams. Contract calculations must start from unrounded quantities and unit prices.

For a two-storey (R+1) 150 m² house in Kénitra (75 m² roof, about 39 m of upstands), the waterproofing and insulation package comes to about 30,000 MAD excl. VAT in mid-range finish with EPS (simulator, 23/10/2026), about 200 MAD per m² of floor area, and about 35,000 MAD excl. VAT with XPS. For your own roof, run an estimate in the simulator; for the overall budget, see structural work cost in Morocco.

What the price includes, and what it excludes

Avoid double counting: waterproofing and insulation systems may be included in the same package. The values shown per item must be checked against the bill of quantities to identify the components already included.

The prices above include supply, installation, labour and the contractor's margin, on a new dry deck with normal access. They exclude:

• stripping an old membrane and repairing a damaged deck, priced after a site visit;
• rainwater downpipes, often in the plumbing package;
• tiles or pavers on an accessible terrace, in the floor finishes package;
• special scaffolding or lifting, and travel costs for a very small area;
• VAT in the excl. VAT columns, architect's and engineering (BET) fees, site set-up and contingency, which the simulator counts separately.

What makes the price vary?

• The system: two-layer SBS, single-layer, synthetic membrane or liquid resin differ in price and use.
• Access: a terrace people walk on, or a roof garden, needs stronger protection than a maintenance-only roof.
• The protection: gravel, screed, pedestal pavers or bedded tiles.
• Insulation: none, EPS or XPS, and its thickness (see our guide on thermal insulation).
• Length of upstands: many parapets, pipes and roof structures add labour.
• The city: the simulator applies a regional factor (Kénitra 0.93; Marrakech 1.01; Tangier 1.02; Casablanca 1.06; Rabat 1.07).
• How the work is procured: with a labour-only subcontractor (tâcheron) and materials you buy, the membrane comes to about 105 MAD/m² excl. VAT in the simulator; the VAT treatment then depends on the provider's tax status, and quality control and guarantees rest more on you.

How is a two-layer membrane installed, step by step?

1. Prepare the deck: dry, clean, swept; coves formed between slab and parapet so the membrane does not crack.
2. Lay the screed to falls towards the rainwater outlets and fit the outlets and overflows.
3. Apply the bitumen primer and let it dry.
4. Lay the vapour barrier and insulation if specified, as the system calls for.
5. Weld the first sheet, then the second with staggered joints, following the manufacturer's data sheet.
6. Form the upstands to the height set by the system and the CPS, and protect their top edge.
7. Carry out the water test: flooding the roof with outlets plugged, or spraying, while the underside is watched. Water-testing methods and duration depend on the approved system and project specifications; the CITURBAREA checklist uses 48 hours of observation by default, to be adapted to the project.
8. Lay the protection only after a successful, witnessed test.

What are the most common mistakes?

• No falls or reversed falls: permanent ponding and faster ageing.
• Upstands too low or unprotected: water gets behind the membrane. The CITURBAREA engine flags any upstand under 15 cm; this is an internal threshold, to be confirmed against the standard or the project CPS.
• Damp or dusty deck: the membrane does not bond and blisters.
• No water test: the defect is found by the occupant, on the ceiling.
• Protection laid too early, or later penetrations (satellite dish, solar water heater) not made good by the roofer.
• Undersized outlets with no overflow: one heavy shower floods over the upstands.

For a development apartment building

R+4 apartment building: a feasibility estimate, not a bill of quantities. The amounts shown come from a simulation scenario (1,200 m², 11 flats, Kénitra, parameters of 23/10/2026). Before any investment decision, the client needs a fixed brief, a preliminary take-off per trade, soil and structural studies, utility connection conditions and the requirements of the competent services, a contingency allowance and comparable quotations. Items already included in one package must not be added a second time.

On a five-storey (R+4) 1,200 m² apartment building in Kénitra (240 m² of roof, about 70 m of upstands, 11 flats, mid-range finish), the CITURBAREA simulator puts the waterproofing and insulation package at about 94,000 MAD excl. VAT (82,000 to 113,000), about 80 MAD per m² of floor area (run on 23/10/2026, contractor, EPS). With XPS it rises to about 111,000 MAD excl. VAT. The roof weighs little per saleable m², but a leak affects the top-floor flats and delays handover: a developer should require a system described in the CPS, a witnessed water test and a signed record for each roof. A residential building of more than three storeys falls within the compulsory all-risks site (TRC) and ten-year liability (RCD) insurance described by the ACAPS, the insurance regulator. To fit this item into your appraisal, ask for a feasibility study, a developer's appraisal or a bill of quantities (DQE).

Developers: have the economic feasibility of your plot analysed: saleable areas, common parts, parking options, structure, utility connections, forecast cost per package and permit risks. Ask for an initial scoping review; detailed studies and costings are covered by a contractually defined assignment.

For a facility (school, clinic, hotel, shop)

Schools, clinics, hotels, shops and warehouses: requirements vary. Fire safety, accessibility, sanitary facilities, ventilation, operational safety and permits depend on the precise use, the number of occupants, floor areas, number of storeys and the activity. Regulatory references must be checked for the project concerned. The CITURBAREA simulator offers an indicative estimate by type of building open to the public (school or nursery, clinic or medical practice, hotel or riad, shop, offices, warehouse or workshop), based on a standard brief and on price and ratio assumptions still to be confirmed: no ratio is a quotation for this kind of project.

For a two-storey (R+1) 1,000 m² private school in Kénitra (the simulator's "school or nursery" ERP type, detached building, 500 m² of roof, about 100 m of upstands), the simulator gives about 184,000 MAD excl. VAT (161,000 to 222,000) for waterproofing and insulation, about 185 MAD per m² of floor area, and about 220,000 MAD excl. VAT with XPS (run on 24/10/2026). This is an indicative estimate: the standard brief and some prices are assumptions still to be confirmed. What changes for a facility:

• the large roof area and the plant on it (air-conditioning units, ducts, panels) multiply the upstands and penetrations to detail;
• the fire behaviour of the build-up (insulation, membrane) comes under the fire and panic safety regulation (decree no. 2-14-499, Official Bulletin no. 6306 of 06/11/2014), depending on the building's classification and the opinion of the competent authorities;
• the inspection body (bureau de contrôle) and the engineering firm (BET) take part in choosing the system; TRC and RCD insurance is compulsory for commercial or hotel buildings according to the ACAPS; for a school or a clinic, check with your insurer;
• phasing matters: a school roof is redone during the holidays, a clinic or a hotel often stays open.

Facility owners: ask for a brief scoping review before any costing: capacity, flows and operation, security and fire safety, maintenance, technical needs, permits and overall operating cost. A specific consultation will determine which studies to commission. For a first order of magnitude, run the simulator's ERP costing, then book a brief scoping appointment.

What does the architect check on site?

The CITURBAREA roof waterproofing checklist is signed before work moves on: falls towards the outlets; dry, clean deck with coves; insulation as specified; membrane matching its data sheet (reference, thickness, reinforcement); upstands and their protection; outlets and overflows; water test carried out as the CPS requires, with no leak on the underside; protection laid after the test. At final acceptance (réception définitive), one year later, the roof and façades are checked again after a winter. For the order of works, see steps to build a house in Morocco.

Which standards and regulations apply in Morocco?

Standards are paid documents: we give their reference and subject only. Their status was checked on 23/10/2026 against the list of mandatory standards published by the Ministry of Industry and Trade, updated on 09/03/2026. Your project specification (CPS) states which are contractual.

• NM 10.8.913-2020: building works, waterproofing of flat and pitched roofs on masonry decks; mandatory.
• NM EN 13956-2016: plastic and rubber roof waterproofing sheets; mandatory for the products concerned.
• NM EN 13969-2020, NM EN 13970-2020, NM EN 13967-2020, NM EN 14909-2020 and NM EN 14967-2020: sheets against rising ground moisture, bitumen vapour barriers, damp-proof courses in walls; mandatory for the products concerned.
• NM EN 13707 (reinforced bitumen roofing sheets) and NM EN 13162 to 13165 (factory-made thermal insulation): Moroccan standards not on that list; voluntary references, contractual when the CPS cites them.
• NF DTU 43.1 (flat roof waterproofing) and NF DTU 43.5 (re-roofing): voluntary French references, not Moroccan law; they become contractual when the CPS cites them.
• Decree no. 2-13-874 of 15/10/2014 (RTCM, Moroccan thermal building regulation), Official Bulletin no. 6306: thermal requirements for the envelope, roof included, by climate zone. This guide gives no value per zone: insulation thickness is set by the project's thermal check.

How do you get a fair price for your roof?

Measure the roof area and the length of parapets, then compare membranes, insulation boards and resins: you can browse supplier products and prices in the materials library (free account). Send the same description to several contractors (see choosing a construction company): same system, same protection, same length of upstands, water test written into the quote. If you live abroad and an existing roof leaks, or you want a quote reviewed, book a video call with the architect, who will go through your photos and drawings with you.

Frequently asked questions