How to Fix a Heaved Deck Post

Heaving deck posts can be a problem for those who have an old or deteriorating deck. These posts may begin to rise from the ground as they become weaker and less stable, which can cause safety hazards and structural problems.

How to Fix a Heaved Deck Post

To fix this issue, it is essential that you first identify the type of heaving post that you are dealing with. There are two types of heaves: raised heel height is above the top of the deck footing, and lateral height is below or at the top.

Once you know what kind of heave you’re looking at, there are various ways to fix it, depending on how severe your problem is. So, this article is for you. You will learn how to fix a heaved deck post with just one simple trick!

Step to Follow on How to Fix a Heaved Deck Post

Step One: Determine the Side of The Boat with The Problem

A heaved deck post is most often caused by a raising of pressure on one side of your boat. Carefully step onto all areas of your deck to detect where the problem area might be. Note that an issue on one side could also cause your deck to become heaved on the opposite side as well, although this is less common.

Determine the problem

I’m not sure what the cause of the issue is on this boat. It could be due to a raised portlight, leading hatch, or any other lowered obstruction on the starboard side of the boat. My best guess is that a raised portlight causes this issue. Also, note the gap, which indicates that the deck has been lifted on the starboard side due to some obstruction.

Step Two: Repair the Cause of The Heaved Deck Post

If you determine that one side of your deck is heaved due to a raised obstruction, such as a portlight or hatch, then carefully remove the offending item and replace it with something less obstructive. Next, carefully use a chisel and hammer to chip away sediment from around affected fittings.

For example, if your starboard deck has been raising due to a portlight being raised, remove the screws of the offending portlight and place it back in its original position. Then, carefully use a chisel and hammer to chip away all the sediment that has been used as filler inside the portlight frame.

Step Three: Adjust the Deck to Its Original Position

Once you determine that your deck is heaving due to a raised obstruction, carefully lift the deck and remove any sediment that has made it inside. If you find screws or other items underneath your decking after removing obstructions, carefully chip them away and replace them or purchase new ones and tighten them back into place.

Carefully lift the deck with help if necessary and use a chisel to chip away any obstructions that you might find under your decking, such as screws, which need replacing. Once you’ve completed these steps, carefully place your deck back into its original position and tighten all screws accordingly.

Step Four: Fill the Holes

Once you’ve carefully realigned your deck post, it’s time to use some fiberglass filler to repair any holes that were under your raised obstruction. Mix the filler according to the manufacturer’s directions and apply it over all of the areas where your deck was heaving due to obstructions.

 Fill the Holes

Once this has dried for the recommended amount of time, apply another dose of fiberglass filler to help smooth your deck back into place. After the first application has dried, apply another coat over all affected areas. This will help smooth out any raised area on your deck and allow for a more level surface overall.

Step Five: Sand the Surface Smooth

Carefully sand the surface of your deck using a power sander and 100-grit sandpaper. Go over all areas affected by raising or issues with your deck post. Once you’ve finished sanding the entire deck, remove any dust from the surface with a cloth rag.

Carefully inspect your deck for any patchy spots that may still exist. If you find that this is the case, use some more fiberglass filler to smooth out any spots that might exist. Once this has dried for twenty-four hours, use a power sander to level the surface of your deck.

Step Six: Apply a Varnish

Even though you’ve repaired any issues on your deck, it’s still good practice to apply an even coat of yacht varnish over your entire surface. This will help seal your deck and protect it from any further damage. Carefully apply a coat of yacht varnish over the whole surface using a paintbrush, ensuring that you go over all patched areas two more times to ensure even coverage.

Once this has dried for twenty-four hours, lightly sand the surface with 100-grit sandpaper. Carefully inspect your surface for any patches. If you find some, apply another coat of varnish over the patchy areas and allow it to dry for twenty-four hours before lightly sanding it again.

Step Seven: Reinstall the Deck

Once you feel confident that your deck has been fixed, reinstall any obstructions causing your boat to heave. This will typically include portlights and hatches. After you’ve reinstalled these objects, re-tighten all screws accordingly.

 Re-tighten All Screws Accordingly.

Reinstall any other parts of your boat that may have been removed during the repair process. Be careful not to jar or bump your deck after you’ve reattached these parts, as this may result in a heave once again. Thanks for reading about how to fix a heaved deck post.

Frequently Asked Question

Will Heaved Concrete Go Back Down?

Heaved concrete usually forms in a layer or stratum at or near the surface and does not penetrate deeply into underlying layers. It often occurs in areas where natural water flow washes away loose material from the surface, leaving only small depressions.

If heaved concrete footing is exposed to frost level, it will shrink due to freezing and thawing, causing further shrinkage and settlement. The final effect can be quite dramatic if this happens during freeze-thaw cycles over many years.

There are two ways you can help prevent heaving: firstly by applying drainage materials such as gravel around heave sites; secondly by avoiding construction on sites with highly vulnerable soils such as sandstone.

Is Sand Susceptible to Frost Heaving?

The frost heave of sand is a geotechnical phenomenon that can occur when the soil type or rock under a building settles due to frost depth action. Frost heave causes movement in the underlying soil or rock, and it can cause subsidence, which may lead to the failure of foundations.

There are three types of frost heaves:

  1. Freezing-thawing heave
  2. Sliding (grouting) heave
  3. Compression (creep) heave.

A freezing-thawing heave occurs when freezing water accumulates on an area of ground and then thaws out as more water is added. The resulting slurry-like material then moves away from its original position under pressure from capillary forces caused by gravity.

Sliding (grouting) heave occurs when two frozen layers move over each other and create a layer cake effect that results in a sliding movement. This type of freeze/thaw motion also creates grout between the two layers, which increases friction and further slows down movement.

Compression (creep) heave happens when soil is constantly compressed by ice without thawing at all, creating permanent settlement into any voids in the ground such as holes or cracks below grade level with low relief features like depressions, crevices, faults, etc., but not including large sinkholes or bedrock disturbances like cave systems because they would have been previously filled with sedimentary deposits that were pushed up during compaction rather than pushed down from above by freeze/thaw cycles alone.

What Type of Soil Is Most Susceptible to Frost Heave?

Frost heave is a phenomenon that occurs when the soil is frozen and thaws, causing it to expand. This can cause the ground to break apart or even lift up, making it difficult for plants to grow.

The type of soil most susceptible to frost heave in clay-rich soils. Clay-rich soils are made up of minerals such as quartz, feldspar, mica, and aluminum oxides. They also contain organic matter like hummus and other plant nutrients, which make them great for holding ground-water but not so good at draining it away once they freeze.

What Are the Main Causes of Frost Heave?

Frost heave is a common term used to describe the movement of groundwater and soil when the temperature falls below freezing.

There are two main causes of frost heave:

  1. When the ground freezes, it expands.
  2. The weight of ice compresses soil or rock under it, creating pressure on its surface and causing it to push up through cracks in the soil or sand.
Ice Compresses Soil


To see if your deck post base needs to be replaced, you can use a level. Place the level on top of the post and look at whether it is sitting straight up or leaning forward. If the post leans forward, there may not be enough pressure in the soil supporting it, so you should consider replacing it with an updated version that has more weight for support.

Remember to always contact a professional contractor before making any changes! The infomercial style of this article has shared information on how to fix a heaved deck post.

You may also check it: How to Fix Cupped Deck Boards

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