A terrace that sheds water instead of holding it.
Terrace leaks are stopped at the details, not by the coating alone. We trace where water is actually entering, correct the falls to your outlets, treat cracks, parapet junctions and pipe penetrations, then apply a system suited to how the terrace is used.
- Free site inspection
- Written, itemised quote
- 1-year workmanship warranty
- Same-day callback
At a glance
What does terrace waterproofing actually involve?
Terrace waterproofing seals the top of your roof slab so rain can't get into it. The coating is the last step and the smallest part of the job. Most of the work happens before it: tracing where water is actually getting in, stripping whatever has failed, treating cracks, parapet junctions and pipe penetrations, and getting the falls running properly to the outlets.
When this is the answer, and when it is not.
Sending you to the wrong service wastes your money and our time. This is how to tell.
This is likely right if
- Damp patches or peeling paint appear on the top-floor ceiling during the rains and dry back afterwards
- The existing terrace coating is chalking, blistering or lifting away at the parapet edge
- Water stands in pools on the terrace after rain instead of reaching the outlets
- A new slab has been handed over and you want it treated before it sees its first monsoon
Something else comes first if
- The water is coming from the overhead tank, its inlet and outlet lines, or an AC drain, that must be traced and repaired by a plumber first, or the coating simply seals over a live source
- The slab is spalling with corroded steel showing, or a crack runs right through and is still moving, that needs a structural engineer's opinion and concrete repair before any membrane goes down
- Something is about to be built on the terrace, a room, a garden, new tank supports or a solar heater frame. Every anchor bolt punctures whatever we lay, so the layout has to be settled first
What the service includes.
Survey and leak tracing
We walk the terrace and the ceiling below together, and check the parapet junction, the outlets, the tank platform and every pipe that comes through the slab. A stain inside rarely sits directly under the point where water is getting in.
Stripping and surface preparation
Failed coating, hollow screed and saturated old brickbat coba taken off, laitance ground back, the slab washed and allowed to dry. A membrane bonds to whatever is beneath it, laid over a loose layer, it lifts with that layer.
Cracks, junctions and penetrations
Cracks cut open and filled, a cove fillet formed where the slab meets the parapet, and reinforcing mesh dressed around pipes, outlets and tank legs. These details are where terraces leak, not the open middle.
Falls and drainage
Ponding areas re-screeded so water runs to the outlets, and the outlet mouths recessed and dressed so the membrane turns down into them instead of stopping short at the edge.
System application
Applied to the coat count in your quotation and turned up the parapet and mumty walls to an agreed height, built up in crossing directions rather than one thick pass that skins over and traps solvent.
Water test and handover
The terrace is ponded with water and the ceiling below inspected before we call it finished. You get the specification you were quoted, in writing, along with a written warranty and the conditions attached to it.
Not included, or quoted separately
- Plumbing repairs, overhead tank leaks, tank overflow and inlet lines, corroded downtake pipes and AC drain lines
- Structural repair, or anything needing a structural engineer's opinion, spalling concrete with exposed steel, a slab that's deflecting
- Making good the ceiling and walls below, plaster, putty and repainting are quoted separately, and only once the slab has dried out
- Terrace garden systems, planters, soil, root barriers and the drainage layers beneath them
- Rainwater harvesting pits, sumps, and the downtake and drain lines below the terrace outlets
The sequence.
Inspection and leak tracing
We look at the terrace and at the affected ceiling below, run water to see where it goes, and check the tank and pipework, so we aren't waterproofing against somebody else's leak.
Specification and quotation
Which system suits your terrace, a cementitious slurry, a reinforced liquid membrane, or a torch-applied sheet under a protective screed, depends on the slab's condition, the foot traffic it takes, and how much of the old layer has to come off. Coats, thickness and upstand height are stated in the quotation.
Stripping and preparation
Old coating and unsound screed removed and carted off, the surface ground and cleaned, then left to dry. The work is planned around a dry spell, because nothing goes down on a wet slab.
Detailing and repairs
Cracks, coving at the parapet, pipe collars, outlet dressing and mesh reinforcement, all done before any field coat, because none of it can be added afterwards without cutting back into finished work.
Falls, screed and curing
Where the terrace holds water, a screed laid to fall towards the outlets and then cured properly. Rushing this puts a hard layer over a wet one, and it cracks.
Coating, water test and handover
Coats applied to the agreed specification, then a ponding test with you present and a walk of the ceiling below before we hand the terrace back.
What moves the price on this job.
We do not publish a rate, because it would change once someone measured your property. These are the variables that decide it.
- The terrace area measured over the slab, plus the parapet upstand and mumty walls that get coated
- Whether the existing layer can be over-coated or has to be broken out and carted down, usually the largest variable
- How much re-screeding the falls need before water stops standing
- The number of details: pipe penetrations, outlets, tank supports, expansion joints and parapet junctions all take longer than open slab
- The system specified, and whether it needs a protective screed or tile over it because the terrace is walked on
- Access, how material and debris move up and down, and whether the tank, drying lines and solar heater must stay usable while we work
Terrace Waterproofing — your questions.
Why is the ceiling stain not under the crack in the terrace?
Water enters at one point, then travels, along the top of the slab under the screed, or through the concrete and sideways until it finds a light point, a crack or a beam edge to come out at. That's why patching the terrace directly above a stain so often changes nothing. We trace the path first, with water if we've to.
Can you coat over the waterproofing that's already there?
Only if it is still bonded. We scrape and tap-test what's there, anything chalky, blistered or sounding hollow has to come off, because a new membrane bonds to the layer beneath it and lifts with that layer when it fails. Where the old work is sound and compatible, over-coating is sensible and we'll say so.
Will waterproofing stop water standing on the terrace?
No, a coating is not a slope. Standing water keeps a detail permanently wet, works its way into any pinhole, and grows algae that makes the surface slippery and holds still more water. If your terrace ponds, we correct it with a screed laid to fall, or by adding an outlet, before any waterproofing goes on.
The ceiling below is still damp after the terrace work. Has it failed?
Usually not. A slab that has been soaking through several monsoons holds a great deal of water, and once the top is sealed it can only dry from the underside, so the patch fades slowly rather than overnight. Don't putty and paint that ceiling until it has dried, new paint over a wet slab blisters, and you'll be doing it twice.
Can the terrace be waterproofed during the monsoon?
Repairs and patching, yes. A full system, no, the slab has to be dry before anything is applied, and the coats need a dry spell to cure. Working in the rain traps moisture underneath, which then lifts the membrane in blisters. We would rather plan the job around the weather than hand you back a coating that's already failing.
Let us look at your walls first.
Tell us about the property and we will set up a free colour and wall inspection. You get a written, itemised quotation afterwards, with no obligation to go ahead.
- We call you back the same day to get a picture of the property and the surfaces.
- We agree a time and come out for the free inspection.
- You get the written scope and itemised quotation.
- Nothing starts until you approve it.