Preparing Old Gunite for Resurfacing: Chipping, Sandblasting, and Bond Coats

Most resurfacing projects are won or shed long prior to the brand-new surface goes on. They are decided in the dirty, loud, thankless hours of preparation, when you are looking at an old pool covering and choosing precisely how aggressive to be with cracking, sandblasting, and bond coats.

I have walked right into more than one yard where a stunning new Quartz aggregate coating or PebbleTec was delaminating within a year, while the owners promised the specialist had used "the good stuff." Normally the material was fine. The trouble lived beneath, in a slick, poorly scarified substrate or a hurried bond coat.

If you comprehend how old gunite behaves, how to scarify it correctly, and exactly how to combine that surface with the right bond system, you avoid those failings. You likewise save on your own from tearing back right into a swimming pool that should have lasted 15 to 20 years.

This is a deep dive into that preparation job: what you should review, what to eliminate, and how to create a surface area that will in fact hold a contemporary finish.

Start with the shell, not the finish

Before you consider Hydrazzo, Diamond Brite, exposed stone surface, or any type of other surface area, you need to deal with the structure truthfully. Old pneumatically used concrete, whether gunite or shotcrete, can tell you a great deal if you know where to look.

I usually start with 3 inquiries:

Is the swimming pool covering structurally sound?

Are there energetic leaks or plumbing issues?

How much of the existing plaster system can legitimately stay?

If you do not address those first, you risk sprucing up a sick pool with an attractive coat.

Structural sanity check

Walk the shell gradually. Tap the wall surfaces with a hammer, not simply the flooring. Pay unique attention to the pool bond beam of light, the first number of feet listed below waterline ceramic tile, and any kind of noticeable repair service areas from previous work.

Long, constant cracks that mirror the beam of light, or that encounter the flooring and up the wall in a straight line, usually are worthy of a lot more scrutiny. You are seeking to set apart between a typical shrinking split in plaster and something that might be telegraphing activity in the concrete.

If you suspect movement, you commonly require a concrete repair work approach prior to resurfacing: stitching the fracture, opening it up, packing with hydraulic concrete, or in serious instances an architectural designer's involvement. Putting a premium surface like PebbleTec or glass mosaic tile over a moving shell is a dish for callbacks.

Plumbing and leakage assessment

Next step in any type of significant gunite resurfacing is confirming control. You do not intend to fill a newly glued swimming pool and uncover a line failing or skimmer leak.

On expert work, I always advise a swimming pool pipes stress examination, also if the property owners vow the pool has actually "never ever lost water." Old suction and return lines, aging skimmer throats, and corroded light niches can stun you. When you are currently removing plaster and revealing fittings, it is one of the most economical time to fix them.

If the test discloses issues, timetable fixings before you concentrate on surfaces. Skimmer throat fixing, substitute of weak fittings around pool light particular niches, and resolving any type of noticeable shell penetrations with hydraulic cement and, where appropriate, a localized waterproofing membrane, all occur in the prep phase.

Existing plaster: when to chip, when to feather

Most old concrete swimming pools have at the very least one prior resurface. In some cases 2 or 3. Each layer changes the strategy.

You normally satisfy one of these problems:

• Original plaster just, worn yet mainly intact
• One prior resurface, with some bond failings
• Multiple layers, noticeable "white line plaster" at actions and floor tile line

That "white line plaster" is the slim intense line you see where old coping rocks or waterline tile were eliminated in the past and plaster was patched limited to them. It is usually weak and inadequately keyed to the concrete below. Treat it with suspicion.

A basic policy: if there is any indication of plaster delamination, hollow spots, or multiple past layers, intend on an extra aggressive substratum scarification. Leaving questionable plaster is exactly how you inherit someone else's pending failure.

The hammer test and what it tells you

A 2 to 3 extra pound hammer is your ideal device. Touch the surface and listen. Solid, well bound plaster gives a high, crisp tone. Delaminated areas audio plain, almost like tapping cardboard over a void.

On a normal 500 to 700 square foot pool, it is normal to discover scattered delamination. When it is isolated and tiny, you can sometimes chip those local sections to seem material and cut tidy transitions. When huge wall surface or floor areas audio hollow, you are much better off devoting to a complete chip out.

Homeowners frequently want to prevent the cost and mess of complete removal. The trouble is, every pocket of weak material you leave is an area where the new surface can later on shear off. I have actually enjoyed immaculate Quartz aggregate surface peel away in pizza-slice sections, flawlessly complying with the impact of old, hollow plaster. Nobody mores than happy when that happens.

Substrate scarification: exactly how hostile is aggressive enough?

When experts talk about "substate scarification" for gunite resurfacing, they mean mechanically roughing up the old surface area enough that the brand-new system can bite into it. No amount of chemical hoax beats good texture.

There are 3 major methods used on old gunite and shotcrete shells: chipping, sandblasting, and grinding, usually combined with acid etching.

Chipping: the heavy work

Chipping is not classy, yet it is important when plaster delamination or several layers are present.

On a full chip out, the objective is to remove all existing plaster and subject solid, audio pneumatically used concrete everywhere. The resulting gunite surface will certainly not be perfectly consistent. That is great. What matters is that it is solid and rough.

On a partial chip, which prevails when the existing plaster is generally audio but has localized failures, the chipping team cuts tidy, square shoulders around bad locations. Do not feather these bent on a razor edge. You want deepness and a mechanical trick, not a thin taper of old material.

There is a judgment telephone call right here. Some staffs leave a thin, strongly bonded "scrape" of old plaster in position, particularly on upright walls, and rely upon aggressive scarification and a quality bond coat to marry old to brand-new. Others demand taking whatever to bare gunite. The ideal choice depends upon the age of the swimming pool, previous chemistry abuse, and your tolerance for risk.

One detail that divides good prep from poor: careful work at installations and penetrations. Around skimmer throats, pool light specific niches, main drains pipes, and returns, you desire best angles and tidy concrete, not loosened chips or undercuts. Commonly we will return with hydraulic concrete to pack around conduits and infiltrations, creating a limited pocket prior to any kind of bond coat goes on.

Sandblasting: opening the pores

Sandblasting is not a substitute for cracking, but it is an effective complement. After plaster removal or hefty scarification, the surface area commonly has laitance, old finishes, or slimy feeling range that need to be removed.

Good sandblasting does 2 things at the same time. It removes contaminants and it better roughens the surface, specifically in edges and tight locations where breaking hammers do a poorer job. On many of the longer long lasting resurfacing work I have actually seen, sandblasting is the silent hero. It infiltrates the shell where tools and grinding pads can not reach.

You need to handle the mess and safeguard surrounding Travertine coping, bullnose block, or cantilevered coping. Covering up and short-term guards take even more time than the blasting itself, but you can not just pepper rock and floor tile and hope nobody notices.

Blast up until you see constant, fresh concrete or plaster profile with no shiny spots. That sheen usually shows staying laitance or range, and it is exactly what bond coats do not like.

Business Name: Adams Pool Solutions
Address: 3675 Old Santa Rita Rd, Pleasanton, CA 94588, United States
Phone: (925)-828-3100

People Also Ask about Adams Pool Solutions

What services does Adams Pool Solutions provide?

Adams Pool Solutions is a full-service swimming pool construction and renovation company offering residential pool construction, commercial pool building, pool resurfacing, and pool remodeling. Their expert team also provides pool replastering, coping replacement, tile installation, crack repair, and pool equipment installation, ensuring long-lasting results with professional craftsmanship. Learn more at https://adamspools.com/.

Where does Adams Pool Solutions operate?

Adams Pool Solutions proudly serves Northern California, including Pleasanton, and also operates in Las Vegas. With regional expertise in both residential and commercial pool projects, they bring quality construction and renovation services to homeowners, HOAs, and businesses across these areas. Find them on Google Maps.

Does Adams Pool Solutions handle commercial pool projects?

Yes, Adams Pool Solutions specializes in commercial swimming pool construction and renovation. Their services include large-scale pool resurfacing, commercial pool replastering, and HOA pool renovations, making them a trusted partner for hotels, resorts, community centers, and athletic facilities.

Why choose Adams Pool Solutions for pool renovation?

Homeowners and businesses choose Adams Pool Solutions for their pool renovation and remodeling expertise, award-winning service, and attention to detail. Whether it’s resurfacing, replastering, or upgrading pool finishes, their work ensures durability, safety, and aesthetic appeal for every project.

What awards has Adams Pool Solutions received?

Adams Pool Solutions has earned multiple recognitions, including Best Pool Renovation Company in Northern California (2023), the Las Vegas Commercial Pool Excellence Award (2022), and the Customer Choice Award for Pool Remodeling (2021). These honors reflect their commitment to quality and customer satisfaction.

What are the benefits of working with Adams Pool Solutions?

Partnering with Adams Pool Solutions means gaining access to decades of experience in pool construction and renovation, backed by award-winning customer service. Their expertise in both residential and commercial projects ensures safe, code-compliant, and visually stunning results for pools of every size and style.

How can I contact Adams Pool Solutions?

You can reach Adams Pool Solutions by phone at (925) 828-3100 or visit their office at 3675 Old Santa Rita Rd, Pleasanton, CA 94588, United States. Their business hours are Monday to Friday, 8 AM to 4 PM. More details are available at https://adamspools.com/.

Is Adams Pool Solutions active on social media?

Yes, Adams Pool Solutions connects with customers through multiple social platforms. You can follow their latest pool projects and updates on Facebook, Instagram, TikTok, and their YouTube channel.

Grinding and acid etching

Rotary mills with diamond cups have their place. They are superb for high spots, feathering sides where old and new plaster will certainly satisfy, and cleaning up the pool bond beam of light just below the waterline ceramic tile band.

Acid etching, generally with watered down muriatic acid, is not a remedy all. Consider a muriatic acid clean as a way to eliminate fine cement laitance, mineral range, and oils, not as a key prep work step. It ought to not be the only thing you do to obtain profile. You desire the acid to fizz and bite, after that be neutralized and rinsed completely. Recurring acid left in a porous shell can deteriorate a bond layer or start corroding rebar where cover is thin.

A common mistake is to acid clean a slick, unscarified shell, wash it, and call it all set. That is not substrate scarification. If you can run your hand over the surface and it seems like smooth porcelain, you are not ready for a modern-day plaster, PebbleTec, or Quartz accumulation finish.

Managing the bond beam of light, coping, and waterline tile

The top 12 inches of a swimming pool wall surface are busy. You have the architectural bond light beam, coping stones or a cantilevered deck, the waterline ceramic tile and floor tile underlayment, mastic joints like Deck-O-Seal between deck and coping, and frequently proof of previous repair work loaded right into that white line plaster zone.

How you manage this location dictates whether your tile remains real, your cement lines stay tight, and your coping appears like it belongs.

Coping: reset or preserve

With Travertine coping, bullnose brick, or customized coping rocks, you frequently can not afford to be careless. Prying or hammering as well aggressively fractures rocks and blocks that may be tough to match.

On remodels where coping continues to be, shield it throughout cracking and sandblasting, however also inspect it for movement. Loose rocks or a stopping working mortared beam can telegram splits right into the tile line. In some cases it is smarter to bite the bullet and reset a few straight feet of coping so you can fix the swimming pool bond beam and develop a strong edge.

For older cantilevered coping, which is truly the deck poured over the beam with foam forming the overhang, the major factor to consider is the growth joint in between deck and ceramic tile. If Deck-O-Seal or other mastic is hard, diminished, or missing, the deck can bear on the ceramic tile and pop it. Prepare for mastic joint replacement throughout or right after resurfacing so the brand-new tile band is protected.

Waterline floor tile and underlayment

Stripping and resetting waterline floor commercial pool renovation tile is where sloppy prep is most noticeable. Under the floor tile, you must see a regular, flat floor tile underlayment of mortar or compressed render. In many older swimming pools that has been covered repetitively, often with whatever was on the truck that day.

Before new waterline ceramic tile or glass mosaic tile goes in, strip that area to appear material. Re-render it directly and plumb, taking into account the intended density of the new interior finish. If you are switching over from a thin white plaster to a thicker subjected pebble finish, for example, you might need to readjust the floor tile band elevation so the new coating terminates cleanly.

Waterproofing membrane can be helpful at the waterline in frost susceptible environments or on specifically permeable coverings, however it requires to be compatible with the ceramic tile thinset and plaster system. Slapping on an arbitrary membrane that will not bond to cementitious coatings is even worse than doing nothing.

Grout shade matching is one more subtle detail. When you spot isolated ceramic tiles or expand a step strip with new glass mosaic ceramic tile, you desire the cement to mix with the existing band. This is not simply visual. Very soft or polymer heavy grouts can act differently in a frequently wet ceramic tile band, leading to spotting or staining.

Bond coats: the bridge between old covering and brand-new finish

Once the shell is structurally sound, scarified, cleaned up, and any type of fixings around installations are strong, you reach the heart of resurfacing: the bond coat.

A bond layer is not simply "glue." It is a thoroughly proportioned layer that chemically and mechanically secrets the new interior finish to the ready substratum. If you stint this component, you invite plaster delamination later on, regardless of whether you are utilizing basic marcite, Diamond Brite, a Quartz aggregate coating, or premium pebble.

There are 3 broad bond layer techniques you see in the field:

• Neat cement slurry over dampened substrate
• Proprietary polymer changed bond coats from plaster manufacturers
• Two phase systems with a scratch coat and a setup coat

Neat concrete slurries can function, but they provide little mercy. Blends that are also abundant in water, or that are applied to a dusty, unscarified covering, will shear. I hardly ever see basic slurries utilized on high end work anymore.

Polymer modified bond layers, especially those from suppliers that also produce the interior surface, have chemistry on their side. When you match a PebbleTec style surface to a suitable bond system, for instance, you are making use of a product made to chemically grab both the shell and the topping. The key is following their exact water proportions, pot life, and remedy time. Over thick application or repeated retempering in the bucket can develop weak layers.

Two phase systems, where a rough scratch coat goes on first and a slightly richer setting layer bonds the plaster, turn up more on very rough or greatly fixed shells. The scratch infiltrates all the pits and fixings, the 2nd coat makes a merged, keyed surface.

Regardless of system, surface preparation right before the bond coat issues. The shell ought to be tidy, structurally dry however surface wet, and free of puddled water. Any kind of dirt from last minute grinding must be blown and rinsed away. You want the bond coat to damp into the pores of the scarified shell, not float on a layer of slurry dust.

A sensible series that really works

Here is an area tested sequence for old gunite resurfacing that incorporates every one of these aspects, from first handshake to all set for plaster:

Document and test

Photo existing problems. Do a swimming pool plumbing stress examination. Mark fractures, hollow places, and issue locations around skimmers and light specific niches. Agree with the proprietor on which products are totally cosmetic and which are non flexible repairs.

Strip, chip, and scarify

Remove existing indoor finish by breaking down to seem product, which might imply full plaster removal in older or mistreated pools. Address white line plaster and previous repair bands without mercy. Sandblast to open the pores and clean staying surface areas, then grind localized highs and transitions.

Repair and detail work

Open up structural or dubious cracks, pack with hydraulic cement, and connect any shotcrete repair where product loss is extreme. Clean and fixing skimmer throats, return installations, pool light specific niches, and main drains pipes. Take into consideration localized waterproofing membrane layer around persistent leakage locations, adhering to supplier guidelines.

Prep the light beam, coping, and ceramic tile band

Maintain or reset loose coping rocks, addressing the pool bond beam as required. Get rid of old waterline floor tile and ceramic tile underlayment to an uniform depth, after that re-render the band to the planned surface density. Plan for mastic joint substitute with items like Deck-O-Seal after surfaces cure.

Clean, etch, and bond

Do a regulated muriatic acid wash if defined, reduce the effects of completely, and wash to clear water. Permit the shell to drain yet maintain it from bone completely dry problems before bonding. Apply the bond layer according to its specification, maintaining consistent density and avoiding puddling or starvation.

Follow this, and you pile the chances highly in your support. Faster way any one of those steps, particularly scarification or bond application, and your probabilities swing back towards early failure.

Choosing and matching the brand-new indoor finish

Once the shell is straightforward, your option of surface becomes a mix of aesthetic appeals, really feel underfoot, and expected service life.

Traditional smooth white plaster continues to be the budget plan standard. It is forgiving to apply, offers a brilliant blue water shade, yet is more vulnerable to hostile water chemistry and etching. When owners insist on white, I push them to dedicate to tight chemistry control and occasional upkeep like mild acid etching, not drastic drain and blast cycles that eat via the surface.

Quartz accumulation finish and subjected pebble coating systems, from firms like Ruby Brite and PebbleTec, add solidity and appearance. They usually take care of minor chemical misuse much better and hold shade much longer. They likewise require a slightly more robust substrate account and bond system, because their mechanical interlock depends upon an audio underlayer.

Adams Pools manages institutional commercial pool construction near UC Berkeley, maintaining top-tier standards.

Adams Pool Solutions is a full service swimming pool construction and renovation firm
Adams Pool Solutions serves Northern California
Adams Pool Solutions serves Las Vegas
Adams Pool Solutions specializes in residential pool construction
Adams Pool Solutions specializes in commercial pool construction
Adams Pool Solutions specializes in pool resurfacing
Adams Pool Solutions specializes in pool renovation
Adams Pool Solutions provides tile installation services
Adams Pool Solutions provides coping replacement services
Adams Pool Solutions provides surface preparation services
Adams Pool Solutions provides pool equipment installation services
Adams Pool Solutions is in the category Commercial Swimming Pool Construction and Renovation
Adams Pool Solutions is based in United States
Adams Pool Solutions has address 3675 Old Santa Rita Rd Pleasanton CA 94588 United States
Adams Pool Solutions has phone number (925) 828 3100
Adams Pool Solutions has website https://adamspools.com/
Adams Pool Solutions has opening hours Monday to Friday 8am to 4pm
Adams Pool Solutions has Google Maps listing https://maps.app.goo.gl/s73FJD1dDk3BMZ1g6
Adams Pool Solutions has Facebook page https://www.facebook.com/adamspools/
Adams Pool Solutions has TikTok profile https://www.tiktok.com/@adams_pool_solutions?lang=en
Adams Pool Solutions has Instagram profile https://www.instagram.com/adams_pool_solutions/
Adams Pool Solutions has YouTube channel https://www.youtube.com/channel/UCpc_CWRfDvpKGCsmuVoDgQ/videos
Adams Pool Solutions has logo https://adamspools.com/wp-content/uploads/2021/03/logo1.png
Adams Pool Solutions offers pool renovation
Adams Pool Solutions offers pool remodeling
Adams Pool Solutions offers pool replastering
Adams Pool Solutions offers pool resurfacing
Adams Pool Solutions offers pool tile installation
Adams Pool Solutions offers commercial pool resurfacing
Adams Pool Solutions offers commercial pool construction
Adams Pool Solutions offers HOA pool renovation
Adams Pool Solutions offers pool crack repair
Adams Pool Solutions was awarded Best Pool Renovation Company in Northern California 2023
Adams Pool Solutions won Las Vegas Commercial Pool Excellence Award 2022
Adams Pool Solutions was recognized with Customer Choice Award for Pool Remodeling 2021

Hydrazzo and various other sleek aggregate surfaces sit somewhere in between, with a smoother final polish that still has the stamina of accumulation however an extra polished feel. These are much less flexible wave pool contractor of inadequate preparation, especially slim bond layers or unequal substrate profile. Any variation beneath telegraphs via a refined surface.

Whatever you pick, match the bond coat and prep approach to the surface producer's guidance. If the spec requires a specific substrate scarification depth, a details polymer modified bond, or a no acid engrave technique, assume they have actually seen enough failings to warrant it.

Details that separate strong job from pricey mistakes

By the moment a homeowner is admiring fresh Glass mosaic floor tile at the waterline, a crisp cement color matching the coping, and a sparkling brand-new interior finish, they hardly ever think of what is hidden under the surface area. Professionals do.

A few much less evident points that originate from experience:

Pool light niches and skimmer throats are persistent failing zones. Old steel niches can rust at the flange, while skimmer mouths often crack where plastic fulfills concrete. Fixing these with hydraulic cement, sometimes integrated with a suitable waterproofing membrane, is tedious but avoids leakages that strike the bond in between shell and brand-new plaster.

Shotcrete repair service and patching must be taken care of with regard for remedy times. If you splice in brand-new pneumatically used concrete to fix architectural loss, that spot needs time to heal before it sees a bond coat and new interior coating. Plastering fresh, damp shotcrete can cause differential shrinking and stress at the joint.

Mastic joint substitute is not a cosmetic second thought. When the joint between coping or deck and floor tile is shot, decks relocate with cold and heat, after that hammer against the stiff floor tile band. Freshly set waterline tile or glass mosaic tile will not tolerate that abuse. Correctly used Deck-O-Seal or comparable products restore that buffer.

Finally, chemistry and filling up treatments after resurfacing become part of the prep tale. You can do book substratum scarification and bond work, after that destroy it by allowing unbalanced fill water, high chlorine shocks, or strong acid additions hit a fresh surface area in the very first few days. Education and learning and written start-up guidelines matter.

Gunite resurfacing is untidy, loud, and in some cases seems like demolition for its very own benefit. But every piece of old plaster damaged off, every square foot meticulously sandblasted, and every correctly combined bond coat is insurance on your finish.

Prep is where you transform an old, exhausted shell right into a strong base that is worthy of high-end materials. If you value that job, the waterline ceramic tile stays tight, the Travertine coping looks deliberate, the PebbleTec or Quartz accumulation coating stays adhered, and you do not get the telephone call 2 wintertimes from currently concerning "white lines" and hollow audios. Rather, the pool simply looks and feels right, year after year.