Clear the drain again or replace the pipe?
A slow kitchen sink or bathroom backflow often starts with a quote for a single clearing visit.
Repeated blockages can add call-out and equipment charges, while opening a floor or ceiling introduces restoration costs.
This calculator compares repeated mechanical clearing and hydro jetting with partial and full pipe replacement over three years.
Use it to check how many paid visits your assumption implies and whether quotes include access, finishes and testing before agreeing to the work.
This is a Korea-based household budget tool using KRW, Korean VAT terms and Korean apartment repair-fund context checked September 5, 2026.
It serves owners, tenants and building managers dealing with indoor drainage.
It does not infer cause probabilities from symptoms, predict pipe life or select an appropriate method.
If leakage or backflow continues, stop using the affected drain and ask building management or a plumber for an inspection.
A lower calculated budget does not establish that delaying repairs is appropriate.
Match the scope of four different quotes
Mechanical clearing
Enter the call-out, equipment and work charge for one visit.
Check whether a minimum charge applies when the blockage remains and whether another section costs extra.
Restored flow after a visit is not a guarantee against recurrence.
Hydro jetting
Match the treated section and equipment access, and confirm debris handling, testing and cleanup.
The contractor must check whether the method suits the existing pipe.
Material and installation year do not produce an operating-pressure recommendation or cause probability here.
Partial replacement
Separate the affected length, material and installation rate per metre, and fixed work charges.
Check connections to retained pipe, floor or ceiling access, tile and wallpaper restoration, and warranty exclusions.
The condition of sections that remain in place needs a separate assessment.
Full replacement
Define the start and end of the quoted full replacement.
All branches inside one unit and a common vertical stack are different scopes with potentially different payers.
Match length, material and restoration quality rather than relying on the same service name.
Input meanings and avoiding double counting
Site notes do not change prices
Location, cast iron, PVC or stainless steel, installation year, floor, main symptom, previous visits and common-area status are notes for the contractor.
They do not create markups or diagnostic scores.
Use zero for an unknown year; otherwise enter a confirmed year from 1900 through 2026.
If several symptoms coexist, record the main one here and tell the contractor about the others.
Lump sums versus itemised prices
A lump-sum quote can go in the fixed work charge.
Do not then add metre rates, removal or restoration already included in it.
If the quote covers pipe materials alone, obtain labour, connections, opening and finishes separately.
Replacement length accepts two decimal places; the summed construction subtotal is rounded to whole KRW.
Per-visit charges versus three-year totals
Clearing call-out, equipment, work, access, restoration and extras repeat at the same amount each visit.
An unusually expensive first visit, future discounts or free warranty visits can differ from this simple model.
Additional maintenance is the three-year VAT-inclusive cash total excluded from those repeated work charges.
Confirmed recoveries and additional leak-damage budgets are also totals for all three years, not annual amounts.
A complete quote and confirmed site suitability are separate checks.
Do not confirm suitability merely because a price was supplied before inspection.
Unknown or mixed VAT quotes show provisional input totals but are excluded from cost-difference and crossing-count comparisons.
Mark a zero-price quote complete only when free work is confirmed; unfilled fields must not be interpreted as free services.
The 36-month calculation, including work now
- Per-visit subtotal = fixed charge + replacement length × rate per metre + opening + restoration + extras
- Construction charge = subtotal + 10% of subtotal only when VAT is excluded
- Per-visit budget = construction charge + construction charge × your contingency rate
- Clearing visits = ceil(36 ÷ repeat interval); replacement visits = 1
- Three-year gross budget = per-visit budget × visits + additional maintenance
- Personal additional budget = max(0, three-year gross budget − confirmed recoveries)
- Budget including leak assumption = personal additional budget + additional leak-damage budget
A 12-month interval schedules work at months zero, 12 and 24: three visits.
Work at month 36 is outside the analysis and is excluded.
An 18-month or 24-month interval gives two visits; a 36-month interval gives only the visit now.
These are assumptions rather than predicted recurrences; compare several intervals using past records and contractor findings.
For a VAT-exclusive quote, 10% is added to the construction subtotal.
VAT-inclusive quotes are not taxed again, and unknown VAT is not silently added.
Contingency is a separate reserve on the VAT-inclusive construction charge, not a confirmed contract amount or tax bill.
Maintenance and leak-damage inputs receive neither additional VAT nor another contingency.
Subtotal, added VAT and contingency are each rounded to whole KRW.
Inflation, discounting and the residual value of new pipes are excluded.
A fictional clearing-versus-replacement example
These figures illustrate the arithmetic and are not market prices.
All quotes exclude VAT, contingency is 10%, and additional maintenance, recoveries and leak budgets are zero.
Site suitability is assumed confirmed for every option in this example.
Fictional three-year budgets including VAT and contingency| Method | Visit subtotal, KRW | Visits | 3-year budget, KRW |
|---|
| Mechanical clearing every 6 months | 200,000 | 6 | 1,452,000 |
| Hydro jetting every 12 months | 350,000 | 3 | 1,270,500 |
| Partial replacement | 1,000,000 | 1 | 1,210,000 |
| Full replacement | 2,200,000 | 1 | 2,662,000 |
Partial replacement comprises KRW 200,000 fixed work, 4 m × KRW 100,000, KRW 100,000 opening, KRW 200,000 restoration and KRW 100,000 extras: KRW 1,000,000 before VAT.
Full replacement comprises KRW 300,000 fixed work, 10 m × KRW 120,000, KRW 200,000 opening, KRW 400,000 restoration and KRW 100,000 extras: KRW 2,200,000 before VAT.
A hydro-jetting visit requires KRW 423,500 including VAT and contingency.
Its third visit reaches the partial-replacement budget of KRW 1,210,000, with a three-year difference of KRW 60,500.
Reaching the full-replacement budget takes seven such visits, beyond the assumed three-year horizon.
This does not establish that partial replacement fixes the cause.
Problems outside the selected section, or a condition that clearing can address, change the appropriate scope.
After loading the fictional example, replace prices and suitability confirmations with your actual quote and inspection findings, even if only some values were edited.
Read the results and prepare your contractor discussion
- Collect site photos, work dates, receipts and flow or camera inspection records.
Past visit counts are not automatically copied into the next three years; choose the future interval separately.
- Obtain at least two written quotes with the same scope, VAT basis, access, restoration, disposal and testing.
Check materials and scope before interpreting a difference in price.
- Select the baseline clearing method and read the personal-budget difference and crossing count.
The count holds three-year maintenance and recoveries fixed; it is not a full lifecycle analysis beyond that horizon.
- Compare the 6-, 12- and 24-month interval sensitivity cards.
If a small change reverses the cost comparison, discuss the uncertainty in recurrence timing with the contractor.
- Print or save the comparison as PDF and request missing work items, warranty terms and extra-charge conditions.
Ask management for evidence of common-area boundaries and contribution payment timing.
The initial work budget is shown before recoveries.
Even confirmed insurance or management payments may arrive after the contractor must be paid.
Annual amounts contain construction budgets only; maintenance, recoveries and leak assumptions with unspecified dates are not arbitrarily allocated to years.
A recovery exceeding the gross budget cannot make personal cost negative or appear as income.
Common drainage and Korean long-term repair funds
A common pipe does not automatically mean a free repair or a fixed personal percentage.
Multi-Family Housing Management Act Article 29 concerns the long-term repair plan for common parts and its review; Article 30 provides for owner-funded reserves and use according to the plan.
Enforcement Decree Article 31 addresses management-rule rates, monthly household accrual calculations and the use-plan approval process.
The monthly reserve accrual formula does not automatically determine the bill for this particular repair.
The annex 10% is not your personal share
The Enforcement Rule Article 7 and Annex 1, effective July 30, 2026, list partial repair at 10 years and a 10% repair percentage for cast-iron and PVC wastewater pipes.
These are repair-plan reference entries, not a subsidy, household share, universal pipe lifetime or clearing interval.
The entries are not extended to stainless steel or automatically used in the cost calculation.
Check your building rules, repair plan, area-boundary evidence and approved work before entering confirmed contributions.
Do not deduct previously paid reserve contributions again alongside the amount allocated to this job.
Landlord–tenant settlement, insurance and lower-unit damage liability require separate factual and contractual checks.
Leave verbal promises or unconfirmed support at zero and update the budget when payment is confirmed.
The calculator horizon is a budgeting assumption independent of the statutory three-year plan review.
Practical scenarios and commonly omitted costs
A repeatedly blocked sink
Use receipts to separate call-out and extra-work fees, then vary the interval.
Cleaning the drain opening and treating a concealed branch are not necessarily the same scope.
Check what the next paid visit would cost under any recurrence warranty and note the limits of equal-cost repetition.
Access through a ceiling
Include protection, opening, finishes and disposal alongside the pipe rate.
Record lower-unit access and permitted work hours in the quote.
Additional leak-damage budget is your allowance for future damage; keep already settled losses separate to avoid counting them again.
A pipe serving several units
Keep the budget scope consistent instead of mixing a unit quote with a whole-building quote.
If management-paid amounts were already removed from the quote, do not deduct them as recoveries again.
Ask for boundary evidence and discuss it with management when classification remains uncertain.
An older property advised to replace pipes
Ask for section-specific findings and the condition of retained pipes rather than assuming age alone requires full replacement.
Compare materials, connections, post-work flow tests, finish quality and written warranties.
Budget and ability to address the cause need separate confirmation.
Frequently asked questions
Does this provide a national average replacement price?
No.
Region, access, diameter, scope, restoration and warranty differences are not converted into an unverified average.
Enter actual quotes; all loaded example prices are fictional.
Can odor or pipe age reveal cause probabilities?
The tool does not calculate those probabilities.
A contractor needs site evidence, such as camera or flow checks, to assess the cause and appropriate method.
Site notes are for the quote discussion only.
Does the repair fund cover every common-pipe job?
Coverage is not automatic.
Check common-area scope, the building repair plan, management rules and approval, then enter the confirmed contribution.
The annex repair percentage is not a personal cost share.
How much lower-unit compensation will replacement prevent?
The tool does not estimate leakage probabilities, liability or damages.
You may add a separate future leak-damage budget to each option.
Insurance and warranty effects are not automatically assumed.
Is the crossing count a recommended replacement date?
It is only a conditional cost threshold with three-year maintenance and recoveries held fixed.
It is not a forecast of recurrence or repair advice.
Continuing leaks or backflow call for site inspection regardless of the budget comparison.
Why is comparison unavailable after I enter a price?
Both options need a complete quote, confirmed site suitability and an included or excluded VAT basis.
Provisional totals are kept separate from comparison to avoid treating an unconfirmed method as a cheaper suitable option.
Official sources and verification date
Current status, articles and the annex were checked directly with the National Law Information OPEN API on September 5, 2026.
Prices and repeat intervals are user inputs, not statutory prices or schedules.
Recheck the individual building scope, rules and payment decisions.