Reviewed and updated October 6, 2026.
Cleaning interlock means protecting both the paver face and the joints. Start by identifying the paving material, existing sealer and jointing product. A method that removes a stain can also damage a finish or wash out sand if those details are ignored.
In This Article
1. Inspect the stones and joints
Look for loose pavers, sunken areas, open joints, existing coating, white haze and damaged edges. Take photos before starting. Cleaning cannot correct movement in the base or drainage problems, and loose stones should be assessed before equipment is used over them.
If the installation is new, check its care instructions. The Techniseal SMARTSAND technical sheet, for example, restricts high-pressure cleaning during the first 30 days. Other jointing products may have different requirements.
2. Choose a cleaner for the actual stain
| What you see | First step | Avoid assuming |
|---|---|---|
| Loose dirt or leaves | Sweep and assess whether a gentle rinse is sufficient. | Every surface needs pressure washing. |
| Organic growth | Identify a cleaner approved for the paving material and surrounding area. | A household chemical recipe suits every finish. |
| Oil or grease | Use a compatible stain treatment after a small test. | Higher pressure alone will remove an absorbed stain. |
| White haze | Identify whether it is efflorescence, residue or a coating issue. | All white marks need the same acid cleaner. |
| Rust marks | Check a rust treatment approved for that stone or paver. | A concrete cleaner is safe for every natural stone. |
Follow the cleaner's label for dilution, dwell time, rinsing and protection of adjacent surfaces. Do not mix cleaning products. Test in an inconspicuous area and let it dry before treating the whole patio or driveway.
3. Use controlled cleaning
A pressure rating alone does not establish a safe method. Nozzle, distance, flow, angle, dwell time, paver condition and any existing coating all affect the result. Start with the least aggressive manufacturer-approved method and stop if the face changes or joint material is displaced.
Avoid directing a concentrated jet into joints. Keep dirty water from repeatedly running across finished sections, and protect adjacent planting, doors and surfaces according to the cleaning product's instructions. A professional assessment is appropriate when the paving material or previous coating is unknown.
4. Assess whether joints need restoration
After cleaning, inspect the joint depth and condition. Re-sanding is a separate part of the scope, not an automatic light dusting of new material over old joints. The chosen product may require particular joint dimensions, removal of old material and compaction.
Plan to use the right material for the paver and installation. A product intended for one type of joint or drainage arrangement may not suit another. Record the product name so its maintenance requirements remain available later.
5. Follow the polymeric sand instructions exactly
Preparation, dry conditions, compaction and water activation vary by product. Do not assume that lightly misting the surface activates the full joint. Use the quantity and application method specified on the current bag or technical sheet.
The Techniseal product guide describes why its fast-setting sands need adequate water promptly during activation. That is a product-specific process, not a reason to flood every sand installation. Clear residue from the paver faces as instructed before activation.
6. Decide whether sealing is appropriate
Sealing is a separate decision. Check compatibility with the paver, any old coating and the jointing material. Compare the intended finish on a small test area: a colour-enhancing finish may look different from a natural-look treatment.
Do not apply sealer over unresolved haze, trapped moisture or loose residue. Follow the longest applicable waiting period in the sand, cleaner and sealer instructions. “Wait 48 hours, then apply two coats” is not a safe universal instruction.
For example, Techniseal Paver Restorer specifies a 30-day wait after newly installed polymeric sand. Its requirement should be checked when that cleaner is part of the planned process.
What to include in a professional quote
Ask whether the quote covers cleaning only, stain treatment, removal and replacement of joint material, repairs, or sealing. These are different tasks. Include photos, approximate dimensions, paving material if known and details of any previous sealer.
For a Kitchener-Waterloo, Cambridge or Guelph property, discuss paver cleaning and interlock sealing as separate scopes. Confirm the expected finish, access restrictions and weather requirements before scheduling.
Frequently asked questions
Can you pressure wash interlock?
Sometimes, but the method must suit the paver, coating and jointing product. Check the manufacturer's care instructions, test an inconspicuous area and avoid directing a concentrated jet into joints.
What PSI is safe for interlock?
There is no single safe pressure for every installation. Nozzle, distance, flow, technique and the condition of the pavers and joints matter alongside pressure.
Do I need to re-sand after cleaning?
Inspect the joints afterward. Depleted or damaged joints may need restoration using a compatible product and its required preparation method.
How soon can I seal after adding polymeric sand?
Follow the sand, cleaner and sealer instructions together. Their waiting periods can differ, so do not assume that 48 hours is enough.
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