How to Use a String Line Level

Updated on April 12, 2019

Setting the grade on a building site typically requires a survey instrument, but setting elevations is possible with only a string line level. Contractors, landscapers, and property owners need the ability to set elevation grades on land. Layout of elevation grades is critical for providing drainage away from buildings and for avoiding pond areas on a property.

Supplies Needed:

  • Good-quality string
  • Wood stakes
  • Hammer
  • Line bubble level (only costs a few dollars)
  • Tape measure

Ground Slopes Needed for Good Drainage Design

In general, use a minimum grade of 0.5% to promote positive drainage. For areas within 10 feet of a structure, the building code may require a minimum slope of 1% to quickly move the water away from the building.

Steps for Using a String Line Level to Check Grade

  1. Tie one end of the string to a wooden stake. Using the hammer, drive the wooden stake into the ground at the highest point of the grade (highest final elevation). Many times, the starting point is near a building corner since the water would need to flow downhill from there.
  2. Measure out a length of string with the tape measure. Usually a length of 50 or 100 feet is desired, making the calculations easier.
  3. Attach the bubble level to the middle of the length of string.Tie the other end of the string to a second wooden stake.
  4. Tie the string so you are able to slide it up and down on the wooden stake. Pull the sting line tight, and drive the stake into the ground in the direction you want the water to flow. There should not be any sag in the line.
  5. Slide the string knot on the downslope stake up or down to get the bubble level perfectly level.
  6. Use the tape measure to find out the difference between the ground the string along the length of the run. Take measurements at least every 10 feet. Calculate the overall slope of the ground by taking the difference between the string and the ground near the second stake and the string and ground near the first stake. Divide this difference by the distance between the two measured points. The direction of water will flow towards the stake with the greater measurement. For example, say the measured points are 50 feet apart. The first ground to string difference is 1.20 feet and the difference at the second stake is 1.66 feet. The difference along the run is 0.46 feet. The grade is equal to 0.46/50 =.0092. Multiply by 100 to get a percent grade. The result of the example is a ground slope of .92 percent.
  7. Move the stakes around and repeat the process of leveling the string line each time a section of grade needs checked. The first stake can be left in place and the second down slope stake moved to check for drainage a corners of buildings.

Tips for Line Levels

  • A longer piece of string allows checking ground slopes for a larger area but is more difficult to avoid a sag in the middle of the line. Any sag in the line will result in an error in the grade checks.
  • A laser line with a built-in bubble level is a faster way to perform this process of checking ground slopes. A strong laser easily produces a light beam for more than 100 feet. Set the laser on a stand or bucket and level. Then measure out 100’ and find the laser beam. Using the laser, the beam of light takes the place of the string line.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Questions & Answers

  • When using a string line level, where must the level be placed?

    The line level or bubble level on the string line can attach anywhere on the line. Make the string as tight as possible after it is leveled, so you have a nice horizontal line from where to make your measurements.


    0 of 8192 characters used
    Post Comment

    No comments yet.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)