How to Seal Cracks in Walls – Expert Tips for a Smooth Finish
How to Seal Cracks in Walls – Expert Tips for a Smooth Finish
Published: 26 Jun 2024 |
Modified: 10 Aug 2025
HomeBlogs
How to Seal Cracks in Walls – Expert Tips for a Smooth Finish
Create Your Dream Home With Our Painting Experts
Create Your Dream Home With Our Painting Experts
Fill the form below to book a free site evaluation by Nerolac Nxtgen painting Services expert
TABLE OF CONTENTS
Cracks in walls, floors, foundations, and other structures are common issues many homeowners eventually have to deal with. While small hairline cracks may not pose significant problems, larger cracks can signal more severe structural defects if left unaddressed.
The good news is that with the right materials and techniques, you can seal cracks around your home like a pro. With some basic tools and the step-by-step guidance in this article, anyone can achieve seamless, professional results.
How to Identify Serious Structural Issues Versus Minor Cracks?
How to Identify Serious Structural Issues Versus Minor Cracks
Here are some tips on how to identify serious structural issues versus minor cracks:
Location - Cracks near corners, around doors/windows, or in multiple connected lines across surfaces likely indicate a more severe problem than isolated hairline cracks.
Width - Cracks wider than a credit card (1/8 inch or thicker) typically mean more movement has occurred and needs addressing. Thin, widthless cracks are often minor.
Pattern - Diagonal cracks that spread out from a point and get narrower toward the top of walls indicate a foundation problem causing shifting or settling. Jagged cracks may also signify structural problems.
Moisture - Look for darkening, water stains, or moss growing near cracks. Water intrusion through cracks could exacerbate underlying issues.
Growth - Monitor cracks over time. If they continue widening or new cracks form nearby, it suggests more substantial settling or movement is happening.
Floor slant - Use a level or place a marble on the floor to check if cracking aligns with uneven settling that causes slopes or gaps at the baseboard.
Understanding Wall Cracks in Your Home
Understanding Wall Cracks in Your Home
The first step is to properly identify the type of crack you're dealing with and determine its probable cause. Cracks generally fall into a few categories:
Hairline cracks: These fragile, widthless cracks are usually caused by natural settlement or minor shifting in the structure over time. Hairline cracks are typically nothing to worry about. Nerolac Perma Crystal Seal is a top-quality solution suited for this purpose. As a cement-based formula that forms protective crystals, it helps resist dampness and prevents the unsightly blooming, known as efflorescence.
Wide cracks: Cracks wider than a credit card signify more substantial movement. These may be caused by heavy settling, foundation issues, water intrusion, or flooding damage. Wider cracks require more extensive filling.
Diagonal cracks: If cracks form diagonally across walls (usually wider at the top and narrow as they reach the floor), this pattern indicates foundation issues, causing the structure to spread apart. Diagonal cracks should be professionally evaluated.
Irregular cracks: Jagged, crooked cracks that zig-zag could signal foundation problems like uneven settling, sinking, or bowing. Again, professional guidance may be needed.
Pay attention to crack locations as well. Cracks near doors/windows, around corners or in multiple connected lines mean larger underlying structural problems.
Tools and Materials You'll Need for Sealing Cracks
Tools and Materials You'll Need for Sealing Cracks
Beyond the actual foaming crack filler, you'll need a few basic tools:
Putty knife or trowel for spreading filler
Flexible putty knife for smoothing filler in tight areas
Clean rags for surface preparation
Painter's tape for creating clean edges (optional)
Protective gloves, respirator for toxic fillers
Hammer and cold chisel to widen cracks (if needed)
Clean the crack thoroughly using a rag to remove any loose debris, dirt, or old caulk. This will promote better adhesion.
Use a cold chisel and hammer to widen hairline cracks to 1/8 gently". This allows the filler to better "grip" the crack edges.
Apply painter's tape on either side for a cleaner finished edge.
Insert the applicator nozzle or open the container and follow on-package instructions to prepare your crack filler.
Apply filler into the crack using a putty knife, trowel or caulking gun. Overfill slightly.
Spread it evenly using the putty knife or trowel continuously, working it deep into the crack.
Allow to fully dry as directed, then carefully shave off excess using a flexible putty knife at a 45° angle, leaving a slightly recessed filler.
Smooth any remaining rough edges until you have a clean, inconspicuous finish. Wipe away any residue. Naturally, Nerolac Perma Crack Filler is highly effective for the job filling and sealing both internal and external plaster cracks.
Choosing the Right Filler for Wall Crack
Choosing the Right Filler for Wall Crack
With so many crack filler options, selecting one designed for your specific material and crack size is important. Here are the points you need to follow:
For hairline drywall/plaster cracks, latex-based fillers provide flexibility and durability against further movement.
Acrylic-latex sealants adhere well to most porous surfaces, such as drywall and wood, and expand/contract with material shifts.
Floor or foundation cracks require stronger mineral or epoxy fillers to withstand traffic and weather/moisture.
Larger cracks may require expanding foam-type fillers like polyurethane that bond securely and form a tight seal in wide gaps.
Concrete cracks need cement-like formulations to match the material's porosity and withstand alkaline conditions.
Foaming polyurethane crack fillers have risen in popularity thanks to their unique ability to self-level and expand up to 3 times their initial volume within cracks. This makes them ideal for filling irregular voids where traditional caulk may fail.
Specialised Crack Fillers for Concrete
Specialised Crack Fillers for Concrete
Concrete poses unique sealing challenges due to its porous composition and tendency to develop cracks from settling and shifting over time. Ordinary fillers may not bond or hold up against concrete's alkaline properties. Here are some pro tips:
Use epoxy-type concrete crack fillers fortified with polymers and grit for strength and flexibility against expansion/contraction.
Go for fast-curing, one-part formulas that don’t require extensive prep work or skill to apply.
Apply on a dry, clean surface protected from rain for at least 24 hours. Moisture inhibits bonding.
Overfill the crack, then grind/sand flush once cured to prevent water infiltration underneath.
Check sealed areas yearly for cracking and reapply filler as needed to maintain moisture barriers.
With some practice, you’ll be filling cracks like a seasoned contractor:
Work in sections; don't apply filler too far before tooling/smoothing.
Push the filler deep into the crack, then tool it flush to create an invisible “patch.”
Avoid overworking dried filler, which could fracture it or leave imperfections.
Remove any residue before it dries to achieve a seamless, natural-looking repair.
Monitor filled cracks and reapply new layers as the structure settles over the years.
Consider professional help for foundation-level cracks to ensure waterproofing.
When to Call a Professional NxtGen Waterproofing Services
While small cracks can often be filled at home, it’s wise to contact a structural engineer if cracks indicate serious foundation defects. Larger foundation cracks, plumbing issues, or moisture infiltration may require waterproofing membrane installation for a permanent solution.
Expert help also makes sense for large commercial or industrial structures where safety is a concern. However, you can successfully seal minor cracks with homework and careful application.
The Bottom Line
Sealing cracks around your home is an achievable DIY project armed with the right tools, materials, and know-how. Identifying crack causes, selecting compatible fillers, and applying them smoothly ensures long-lasting, professional results. With some practice, you’ll tackle cosmetic cracks like the pros in no time.
Nerolac has been providing innovative DIY and professional-grade crack-filling and waterproofing solutions. To learn more about Nerolac's range of products tailored for different surfaces like walls, floors and concrete, visit nerolac.com or speak to your nearest Nerolac representative.
Nerolac Paints, a leading paint company in India offers a wide range of wall paint colours & painting services & solutions for homes & offices.
Colour Combination for Walls: 10 Beautiful House Colour Combination Ideas
You will be redirected to a webpage/domain hosted by a third-party service provider (“Service Provider”) for limited purposes related to your interaction with Kansai Nerolac Paints.
Please note that while the Company’s logo may appear on the Service Provider’s page, it is not a Company-controlled page and is operated independently by the Service Provider.
On the Service Provider’s page, you will be provided with options for submitting your data, including uploading documents or providing information through various means.
While these options are enabled through a service provider, the Company does not endorse any specific option, and you are requested to choose independently and at your sole discretion.
Any actions taken on the Service Provider’s page, including the submission of data, shall be a matter between you and the Service Provider, and the Company will not be a party to this relationship.
You are responsible for the consent you provide on the Service Provider’s page, and any acceptance of terms beyond the purpose of use by the Company shall be deemed a contract between you and the Service Provider.
By providing your data through any of the available modes, you agree to share and disclose your information with the Company and the Service Provider for the purposes outlined above.
The Company may process, retain, and use the information as per its discretion.
For any modification, correction or erasure of the provided information, please raise you request by sending an email to [email protected]
Consent
In this Consent the following capitalized terms shall have the meanings assigned to them hereunder: By 'personal information' we mean names, addresses, email addresses, job experience and history and any other personal information you voluntarily provide about you and your skills and interests .“Data” shall mean all personal data, transactional data, Derivative Data, any other information, etc., in relation to me/us, including the following in relation to past Products:
By providing the consent you agree to providing your personal data which can be used by KNPL for the purposes mentioned hereafter and confirm that this consent is being given freely by you without any pressure, influence, or coercion from any other person, and that the consent is informed and unconditional.
Information submitted while making any application or request to the KNPL for any Product. Collection of information from personal correspondence (emails, letters) or third-party communications related to user activities on the website. Information may be used to offer products/services from the company and joint sponsors. Communicate with customers about orders, products, services, and promotional offers. Enhance and personalize the shopping and viewing experience on the website.
Additional information collected during transactions includes billing address, payment instrument details, and tracking information, handling orders, delivering products/services, and processing payments.
Information from messages or feedback provided by users is collected and retained for dispute resolution and customer support.
any information obtained/received by KNPL from any other source.
Collection of demographic and other data for advertising and promotional purposes. It can be used to show relevant content and customer reviews, suggest merchandise and services of interest, Improve the website and prevent/detect fraud or abuse, enable third parties to perform technical or logistical functions on behalf of the company.
We may share your personal information with vendors or service providers such as companies who help us with database administration. We may also share your personal information with other Kansai Nerolac companies in other countries where data privacy laws may not be equivalent to those in force in India.
any Derivative Data.
DEFINITIONS
“Derivative Data” shall mean any insights, analytics, performance metrics, behavioural projections, customer profiling, and reports (prepared by the Company internally or by third parties) that are generated through the analysis of data collected from customers, sales transactions, market research, and other relevant sources. This includes, but is not limited to, colour preference trends, purchase frequency, customer demographics, product usage patterns, and feedback analysis. Derivative Data may also include predictive analytics regarding future buying behaviour, inventory optimization, and market demand forecasts, whether derived from the information collected from customers or in combination with any other information sourced from external databases, market research firms, or other entities, whether by the Company or other persons. The process of arriving at and generating such Derivative Data through any of the above sub-processes/methods shall be referred to as “Derivation”.
“Specified Purposes” shall collectively mean the collection of personal data for various essential functions, including customer identification and verification to ensure eligibility for services or promotions, processing and fulfilling orders accurately, and enhancing customer engagement through tailored marketing campaigns and personalized offers. The data will also be utilized for monitoring sales trends and inventory management to optimize stock availability, providing customer support and service to address inquiries and resolve issues, and gathering feedback for product improvement and innovation. Additionally, the company will conduct market research and analysis to understand trends and customer preferences, implement risk assessment measures to detect and prevent fraud, and ensure compliance with legal obligations, including data protection and consumer rights. Personal data will support the management of loyalty programs and promotions, enhance the digital experience on the website through personalization, and facilitate data sharing with third-party partners for operational efficiency. Furthermore, the company will collect data for sustainability and environmental reporting, engage in necessary legal and regulatory compliance activities, and utilize analytics to monitor website performance and overall business effectiveness. aggregators, payment gateways, payments systems, performance of any legal and/or regulatory obligations, filings, reporting, etc., whether any of these are undertaken internally or through any Processing Entity.
"Processing” shall mean any operation or set of operations performed on Data, and includes operations such as collection, recording, organisation, structuring, storage, adaptation, retrieval, use, alignment or combination, indexing, sharing, disclosure by transmission, dissemination or otherwise making available, restriction, erasure or destruction and the term “Process” and “Processed” shall be construed accordingly.
“Processing Entity” shall mean any third party company(ies), bureau(s), consultant(s), vendor(s), agent(s), fintech entity(ies), co-brand entity(ies)/partner(s), distributor(s), selling/ marketing agent(s), any partner(s), collaborator(s), merchant(s), aggregator(s), lead generator(s), sourcing entity(ies), client(s), customer(s) or other person(s) with whom the KNPL has any direct or indirect arrangement or tie-up or contract for any products or services/ intermediary(ies) in any ecosystem of which KNPL is a part, and such Processing Entities’ service providers, consultants, vendors, etc.
“Product(s)” shall mean all types of paint and related products offered by the Company, including but not limited to topcoat, under coat, interior and exterior paints, primers, sealants, varnishes, specialty coatings, tools and ancillaries, wood finishes and construction chemicals. This definition encompasses products sold directly through the Company’s online platform, as well as those distributed through authorized dealers, retailers, contractors or other third-party vendors. The Products may also include complementary items such as paintbrushes, rollers, paint trays, and other application tools, as well as services related to colour consultation, custom mixing, and professional painting services. The Products that have been applied for, requested, or purchased by me/us (including where the initiation of any transaction is not directly with the Company but is with a relevant distributor or retailer) shall be referred to as “Requested Products,” while any Products (including future offerings) other than the Requested Products shall be referred to as “Other Products.”
CONSENT
I hereby authorize Kansai Nerolac Paints Limited (“Company”) to process my personal data (“Data”) or any part thereof for any of the Specified Purposes:
SPECIFIED PURPOSE
In connection with the assessment or processing of my application/request for any Requested Product, or to take any steps prior to entering into any contract, or to determine eligibility for the Requested Products, or in connection with the execution or furtherance of a contract/transaction, including performance by the Company or me/us or any other intermediaries, of any contract or part thereof, or any regulatory or legal obligations in relation to any Requested Product availed or in pursuance thereof;
In connection with the derivation and sharing of any derivative data (between the Company and any processing entity) related to the purposes.
In connection with contacting me, establishing communication, and monitoring my interactions through email, postal address, telephone, social media, notifications, and other electronic.
PURPOSES
I authorize the Processing Entities to process my Data or any part thereof for any of the Specified Purposes.
For the purposes covered above, it shall be deemed that I have furnished all the Data separately under this consent.
I confirm that the Data provided and that will be provided by me from time to time is accurate, updated, and complete in all respects.
I agree that the consents/authorizations for the Specified Purposes shall survive beyond the validity of such application/tenure of the Product/consummation of any transaction, to the extent any of the Specified Purposes survive.
The consents given or denied under this document do not limit any other consents obtained or given.
I acknowledge and confirm that all the Specified Purposes are lawful purposes.
I understand and agree that the processing of Data is necessary for the Specified Purposes.
I acknowledge that the request for consent or my giving of this consent does not limit or prejudice any grounds or bases that the Company or any Processing Entities may have for processing the Data without consent. This consent is in addition to any such grounds or bases. For clarity, even if this consent is withdrawn, the Company and/or the Processing Entities may continue to process the Data for the performance of contracts related to the Requested Products or for taking any steps pursuant to the contract or for protecting the legitimate interests of the Company.
I acknowledge that since this consent is the basis for the Company to enter a contract related to the Requested Products, it is necessary to process the Data for the purposes of the contract. Withdrawal of this consent will not prevent the Company and/or Processing Entities from continuing to process the Data for the purposes of the contract.
Get in Touch
Get in Touch
Store Locator
Store Locator
Download App
Download App
×
Get in Touch
Looking for something else? Drop your query and we will contact you.