Rain running off the edge of a corrugated roof — Stock photo · rain running off a sheet roof

ROOFS · WALLS · WINDOWS · BATHROOMS · BALCONIES · METAL ROOFS

Find where the water gets in Then decide how to fix it

Tap a part of the house to see common signs and demo price ranges, with quick and full fixes priced apart If the building is 30 years or older, check the renovation subsidy first

Where does it leak?

Pick a part to see common signs and demo price ranges

30+ years old? Check the renovation subsidy →Urgent repair after a storm →

Demo website: afterrain is a fictional contractor that takes no jobs and no money

01 / HOW WE WORK

Find where the water comes from then choose a quick or full fix

A contractor for roofs, walls, windows, bathrooms, balconies and metal roofs. We inspect first to find the water's path, then put the quick fix and the full fix — method, price and warranty — side by side on the quotation

Inspect before quoting
Quick and full fix priced apart
Warranty written into the contract

Services and methods

02 / SIX PLACES THAT LEAK

Six places that leak each fixed its own way

Prices are demo ranges; the quotation after an inspection is what counts

01
Flat roofs
Ceiling stains on the top floor, dripping after rain; an aged membrane or poor drainage
Full fix, demo: NT$2,200–3,800 per pingFull fix: 3–5 dry days (demo)
Estimate this
Stock photo
02
Exterior walls
Damp on the inside of outer walls, lifting tiles; water at AC holes and grille fixings
Full fix, demo: NT$3,500–6,500 per pingUpper floors need scaffolding or a lift
Estimate this
Stock photo
03
Window frames
Leaks at the corners in rain, damp below the sill; aged sealant outside
Quick fix, demo: NT$2,500–5,000 a windowA spray test finds the entry point
Estimate this
Stock photo

All methods and prices

03 / LEAK ESTIMATE

Tap a part of the house tick the signs, see the range

Prices come in three parts: inspection, quick fix and full fix; signs of water in the structure point to the full fix

Illustration: a 4-storey apartment section and a metal-roofed shed · Tap a part of the drawing, or use the buttons above

Tick what you see · Flat roofsStains or efflorescence on the top-floor ceilingDripping from the ceiling after heavy rainCracks, blisters or peeling on the roof surfacePonding or leaves around the drainCracks on the inside of the parapet

SizeRoof area (1 ping ≈ 3.3 m²)

ping

Demo price range · Flat roofs

Inspection: NT$3,000–6,000
Quick fix: NT$8,000–25,000
Full fix: NT$59,000–106,000

Tick what you see, or book an inspection

Nothing ticked yet

Demo range — the quotation after an inspection is what counts

How we check

Visual check and moisture readings, a ponding test if needed, to find where water enters the slab

Quick fix

Clear drains and outlets, fill cracks, reinforce the failed patch

Time 1 day · Warranty (demo) 1 yr

Full fix

Strip the old layer, prime, two coats of membrane with fabric reinforcement, a reflective top coat

Time 3–5 dry days · Warranty (demo) 5 yr

What moves the price

Area, and whether the old layer comes off
Whether a reflective top coat is added
Getting materials up (is there a lift)

05 / RENOVATION SUBSIDY

30 years or older? See if a subsidy applies

The Ministry of the Interior's old-building renewal programme funds repairs to 4–6 storey apartment buildings and houses of up to 6 storeys; roof waterproofing and insulation is one of the items. Answer four questions

Programme: Approved by the Executive Yuan on 2026-03-16 with a NT$5bn special budget
Runs to: 31 December 2027

How to apply

Older apartment blocks with rows of windows and air-conditioners — Stock photo · not a subsidised building

06 / CASES AND AREAS

Cases where we found the cause district only

Demo cases are fictional; filter by part and district. On a live site cases give the district only, with the owner's written consent for photos and details

All cases

Demo case (fictional) · 01
Top floor, 4-storey apartment
Banqiao · 38 years old · May 2026
Cause found
The membrane split around the drain and rain ran into the slab
Fix
Stripped, two-coat membrane, reflective top coat
Flat roofs4 daysWarranty (demo) 5 yr
Demo case (fictional) · 02
Outer wall, 5-storey apartment
Zhonghe · 34 years old · June 2026
Cause found
An unsealed AC hole let driving rain follow the pipe in
Fix
Sealed the hole, treated the tile joints around it
Exterior walls2 daysWarranty (demo) 3 yr
Demo case (fictional) · 03
3rd-floor bathroom, 4-storey apartment
Yonghe · 41 years old · April 2026
Cause found
The pressure test found a broken hot-water pipe, not the membrane
Fix
Replaced the pipe, redid the membrane and tiles locally
Bathrooms3 daysWarranty (demo) 3 yr

A gutter overflowing in heavy rain — Stock photo · an overflowing gutter

07 / AFTER A STORM

Stop the water first then find the cause

On an urgent visit we

Stop it for now: cover and divert
Clear drains and gutters
Photograph it for the committee or insurer

Before we arrive

Switch off power near the leak
Move appliances and valuables
Photograph where and how far it leaks

Urgent repair only stops the current leak; a full inspection is still advised. Times and charges depend on the weather (demo)

08 / WARRANTY AND LICENCES

The warranty in writing

Warranty and terms

A metal downpipe on an outside wall — Stock photo · a downpipe

afterrain · 霽簷防水工程

Warranty template (demo)

Work: Roof waterproofing, full fix
Where: New Taipei, ○○ District (district only)
Extent: 20 ping of roof and the parapet inside
Method and materials: Two-coat membrane with fabric, reflective top coat
Period: 5 years from acceptance (demo)
Covers: Leaks in the treated area caused by the work
Not covered: Earthquakes or structural movement, other people's work, damage
Follow-up: One check after the first rainy season

09 / QUESTIONS

Asked before booking

Terms are examples; adjust to the company at launch

Tell us where it leaks then pick a time

Pick the part, the signs and a time, attach photos and generate a demo booking

Book an inspection

A white rooftop with a ladder under a blue sky — Stock photo · a rooftop after rain

After the rain you can tell a good repair