Post Construction Window Cleaning · Peterborough, NH
Post Construction Window Cleaning in Peterborough, NH
Paint, mortar, adhesive and stucco cut off the glass with steel wool and a razor. Not a wash. A glass scratch liability waiver is signed before any blade touches a pane.
At Joslin & Co, we do post construction window cleaning for builders, general contractors, renovators and homeowners in Peterborough, New Hampshire. This is the job where paint, mortar, adhesive, silicone and stucco have to come off the glass after the trades are finished. It is abrasive removal work rather than window cleaning, and it is priced and handled differently.
Post construction glass is not dirty, it is contaminated. Paint has cured into a film, mortar has gone off, adhesive has set. None of that responds to detergent, so the job is removal rather than cleaning, and the method that removes it is the same method that can damage glass if the person holding the blade does not know what to look for.
Why a normal clean will not do it
Soap and a squeegee will not touch construction residue
Every builder has watched somebody try. A bucket, a squeegee and a lot of optimism, and at the end of it the glass looks exactly the same because none of what is on it was ever going to wash off.
| What is on the glass | Why washing fails |
|---|---|
| Paint overspray | Cured film bonded to the surface, not dirt sitting on it |
| Mortar and concrete splatter | Cementitious, and it etches the longer it sits |
| Adhesive and label residue | Needs solvent and a blade, not detergent |
| Silicone and caulk smears | Smears further under a cloth |
| Stucco and plaster | Hardens into a mechanical bond with the glass |
Delay makes it worse in a specific way rather than a general one. Cement-based splatter etches the glass beneath it over time, so what would have been removal becomes removal plus permanent marking. Booking it as the trades finish is the cheapest decision available.
How it is actually done
Steel wool and a razor, in that order, with the glass kept wet
Wet the glass, work it with fine steel wool to take the bulk off, then bring a razor to what survives, still wet, held shallow, pulled one way. Dry glass and a back-and-forth motion are the two habits that turn this job into a replacement bill.
The work is slow and it is deliberate. There is no way to rush a blade across glass safely, which is why post construction pricing has almost nothing to do with how many windows there are and almost everything to do with what is on them and how long it has been there.
The part almost nobody explains
Fabricating debris, and why the scratch argument happens at all
If you take one thing from this page, take this. It explains nearly every argument that has ever happened between a builder and a window cleaner about scratched glass.
During manufacture, tempered glass passes through a furnace on rollers. Particles of glass can fuse to the surface in that process and stay there. They are a manufacturing defect and they are present before anybody cleans anything. Drag a blade over a pane carrying fabricating debris and those particles dislodge and travel under the edge, cutting the surface as they go.
The detection is tactile rather than visual. A pane with fabricating debris feels and sounds gritty under the blade, and that is the signal to stop and reassess rather than push on. The reason this argument recurs across the trade is that glass carrying these fines still passes industry standards, because the particles do not affect clarity or strength. So the pane is not defective by the standard, and the scratch is real, and the two facts sit there contradicting each other.
Understanding it is what turns the risk into something manageable. You test before committing, you stop the moment the feel changes, and you agree who carries the risk up front instead of arguing about it later. That agreement is the waiver.
How we handle the risk
We use a glass scratch liability waiver, and we would rather explain it than bury it
Bringing up a glass scratch liability waiver can read as a company covering its back. Fair enough. It is also the only straight way to deal with a defect that is already in the pane before a cleaner turns up.
| What the waiver does | What it does not do |
|---|---|
| Puts the fabricating debris risk in writing before work starts | Excuse careless work or poor technique |
| Records that scraping is the only method that removes the residue | Remove our general liability cover for damage we cause |
| Makes the decision yours, with the risk stated | Get signed after the fact |
Standard practice across the trade is a signed waiver on any job involving significant scraping. We use one, we go through it before work starts rather than sliding it across afterwards, and we would rather explain what it is for than have you find out what it means from an argument.
Who this is for
Builders, contractors, renovators and homeowners at handover
| If you are | What usually matters most |
|---|---|
| A general contractor | Getting the glass signed off at handover without a callback |
| A window or glazing installer | That somebody understands fabricating debris before a blade is used |
| A renovator | Old glass and new residue on the same job |
| A homeowner after a build | That the windows you paid for actually look new |
The opening conversation is identical in every case: what is on the panes, how long it has been sitting, and whether the glass is tempered. Those three answers shape everything that follows.
Where this work comes from in Peterborough
Renovation produces the same glass as new build
Not much gets built new here. Only 9.5% of the housing has gone up since 2000, while 42.6% predates 1940. What that means is that this work arrives through renovation rather than new construction, and a gut renovation leaves glass in exactly the same state a new build does.
Either way the useful thing on the first call is not the window count. It is what is on the glass, roughly how long it has been sitting there, and whether the units are tempered. Residue that has had a summer to cure is a different job from residue a week old.
Before you hire anyone
Ask for both policies by name, not just “are you insured”
“Insured” matters more on this job than on any other kind of window cleaning, because this is the job where glass actually gets damaged.
General liability pays for damage to your property. Workers’ compensation pays for the person doing the work if they are hurt while they are there. Two separate policies, and a company can carry one without the other.
Abrasive removal is deliberate contact between a blade and a pane. That is precisely the situation general liability exists for, and it is why the cheapest quote on a post construction job is rarely the cheapest outcome. workers’ compensation matters for the same reason it always does: somebody is on a ladder on your site.
We carry both. $1,000,000 in general liability and workers’ compensation, and a certificate of insurance is available on request. Ask us for it, and ask everyone else for it too.
Nico Joslin has cleaned windows for ten years and started Joslin & Co in March 2024. It is family-owned and owner-operated, and it runs out of 61 Appleton Rd Unit 8, New Ipswich, NH 03071, which is a real address with a real phone behind it.
Questions
Common questions about post construction window cleaning in Peterborough
What does post construction window cleaning cost?
There is no honest starting figure for this one. What decides it is the type of residue and how long it has been curing, not the window count, and those two things vary enormously between jobs. Ring us with the details and we will tell you what it involves.
Can you not just wash it off?
No. Construction residue is bonded to the surface rather than sitting on it. Paint has cured into a film, mortar has gone off, adhesive needs solvent. Detergent and a squeegee move dirt, and none of this is dirt.
Will scraping scratch my windows?
On sound glass, worked correctly, it should not. The real hazard is fabricating debris: particles fused into the surface of tempered glass in the furnace during manufacture, present long before a cleaner arrives. A blade can drag one of those and score the pane. It is found by feel rather than sight, it is a manufacturing defect rather than cleaner error, and it is exactly why a glass scratch liability waiver exists.
What is a glass scratch liability waiver?
A document signed before work starts that sets out the fabricating debris risk in writing, records that scraping is the only method that removes the residue, and leaves the decision with you. It is normal practice in this trade on any job involving significant scraping. It does not excuse careless work.
Why would glass with a defect still be sold?
Because fabricating debris does not affect how clear the glass is or how strong it is, so a pane carrying it still meets industry standards. That is exactly why the argument keeps happening: the glass is not defective by the standard, and the scratch is still real.
How do you know if glass has fabricating debris?
By feel and sound under the blade rather than by looking at it. A pane carrying it goes gritty, and that is the point to stop and reassess instead of pushing through. It is a large part of what experience is worth on this job.
How soon after the build should it be done?
Sooner is better and it is not close. Residue keeps curing and mortar etches the longer it sits, so the same job gets harder and slower with time. Booking it as the trades finish rather than weeks later is the single biggest thing that affects what it takes.
Do you do this on new builds and renovations both?
Yes. A gut renovation leaves glass in the same state a new build does, and the removal is the same work either way.
Are you insured for this?
Yes. $1,000,000 in general liability plus workers’ compensation, with a certificate of insurance available on request. On abrasive work that is not a formality, it is the point.
Coverage
Peterborough and the wider service area
Joslin & Co works out of New Ipswich, New Hampshire, across southern New Hampshire and north-central Massachusetts. Keene, NH and Milford, NH are also in the service area, and the full list is on the service areas page. If your town is not on it, ask.
Residential window cleaning in Peterborough
Glass inside and out, screens and storm windows, from $250.
Commercial window cleaning in Peterborough
Storefront glass on a schedule, and buildings up to five stories.
Hard water stain removal in Peterborough
Mineral scale that a wash will not lift.
Post construction window cleaning
How the service works across the whole service area.
Get a price for your Peterborough project
Call and tell us what is on the glass, roughly how long it has been there, and whether the units are tempered. That is enough for us to tell you how it gets handled and what it takes.