Cement Ramp

July, 2023

After the build of my workshop, I realized I needed an access ramp to more easily move things in/out with carts. I chose to pour cement to give me the strength needed for heavy loads I’m planning. I’ve never worked with cement before, so this was a first-time experience for me. After researching, I was surprised to learn that this was not going to be a quick weekend project – my journey took over 30 days to complete this mini-project.

I want to acknowledge some great YouTube videos that helped me build the confidence to tackle this project on my own. This video from “MrKistel” gave great advice about using a mixing drill and bucket, which I used. This video from “Jesse does DIY” was also great as it showed step-by-step for a simple project – I watched this one about 10 times. This video from “DO IT ALL SEALING” was helpful for showing how to build a ramp. Finally, this video from “ToolboxDIY” was very helpful for finding the correct sealant. I feel this project would not have come out nearly as well as it did without these helpful videos.

Design

I wanted the ramp to extend from my existing foundation down to grass level across the full width of the double-doors. I used a can of spray paint to mark the grass where I wanted it in order to help decide how long to make the ramp and how much of a slope to create. I settled on these dimensions:

Because the yard is at a gentle slope, I attempted to make the bottom right corner about level with the grass line to minimize corner exposure on the bottom left.

Next, I did some math and calculated the volume of this irregular shape so I could plan for material. I approached it by breaking the shape into 2 pieces, calculating the volume for each, then adding them together to get the final result: 10.4 cu. ft.

Site Preparation

Next, I used a square head shovel to excavate the area where the cement would be poured. I built a 3-sided form from a 2×4 and some 1×10 stock. I carefully cut the angle of the 1×10 to match the ramp slope so I could use it to screen the surface later. With scrap wood, I cut some triangular stakes for supporting the form. I butted the form sides up against the siding which help to secure it nicely.

Next, I had to tackle the problem of how to make sure the new cement sticks to the existing foundation. I was surprised to learn that cement does not bond well to other cement after it is cured. Luckily, there are some products on the market specifically designed for this including Quickcrete Bonding Adhesive (990201). I applied it with a roller brush on the existing cement foundation – it went on milky white, but dried clear. The 1 qt. bottle was far more than I needed for this small project.

Next, I bought 2 bags of larger gravel (designed for drainage) and 4 bags of pea gravel. I spread the gravel (larger first, then smaller) across the bottom, including under the forms as needed. This gave me a nice, level bed for the cement.

Finally, I bought a single piece of 4′ x 7′ cement wire mesh and used a bolt cutter to snip it to fit inside the form. This stuff was rusty and left marks everywhere, so I handled with gloves and wrapped it in a tarp for transport. I read that there is controversy about the use of this since it can cause issues if it gets wet and cause the cement to crumble. However, I went ahead with it since this application really needs as much strength as I can give it. I thought about doing some fancy stuff like bending it to align with the slope of the ramp, but in the end just let it lay flat on the gravel.

Concrete

Next, I referred to the Quickcrete web site for help with estimating the number of bags I needed to buy. I plugged in my square footage and it told me I needed 14 bags (50 lb) for 10.4 square feet at 6″ deep. Something was weird about this and tickled the back of my brain – I’m sure it’s mothing, but I opted to buy an extra bag “just in case”. I opted for the Quickcrete High Strengh 50lb bag size to make it easier on my back. I stayed with the Quickcrete brand to match the bonding adhesive I applied earlier to maximize the chance of good adhesion.

Thanks to the great video tutorial (mentioned above) I had purchased a 1600W hand-held cement mixer, Heavy-duty mixing bit, and 10 Gallon plastic bucket in advance of the project. These tools really saved my back and accelerated the whole process. I would very much have preferred to rent a small cement mixer, but found that none were available in my area.

My process was:

Fill the bottom of the bucket with some water
Cut the bag open and dump it into the bucket
Spray some more water on top to keep the dust down
Mix for a few minutes while adding water until it was the consistency of oatmeal.
Dump the bucket into the hole
Repeat

I used a hoe to help spread the material evenly inside the form, and to help tamp it down. I also benefited from a small shovel that I used to occasionally hand-mix when the mixing bit couldn’t get all the way down to the bottom of the bucket.

This worked really well and I was able to get all 15 bags mixed and poured in about an hour. That’s when I realized – I didn’t have enough cement! Looking back now, I realize I messed up by confusing “square footage” with “cubic footage” – ugh! I needed 10.4 cubic feet of cement, but 14 bags only gave me about 9.7 cubic feet. So, I ran back to the store and bought another 8 bags. I ended up using 6.5 of them and returning one. Frankly, that math didn’t add-up either, so I’m not sure where I went wrong. I had to move fast since the bottom layer was starting to cure and I wanted to finish the pour.

After the level reached the top, I took a long 2×4 and used it as a screen to settle the material using a “sawing” motion. I learned I should only screen “uphill” on the ramp to avoid shifting too much concrete to the bottom. I carefully added and subtracted material so I got it to fill up to the metal floor plate of the doorway.

I used a rounded trowel to smooth the surface. Maybe I needed to wait a bit to do this, but I found it had quite a learning curve – difficult to get a consistent angle which meant it kept gouging the surface that was trying to finish and I’d have to smooth more to repair.

Next, I used a concrete edger to clean up the edges. I probably waiting a bit too long to do this step (about an hour) because parts were quite difficult to work out – some bad advice from the videos I watched told me it could be done 2-3 hours afterward. I ended up spraying a bit of water to soften the concrete a bit for the edging to get smooth. I struggled with edging the front corners, but with some persistence, got them to be acceptable.

I used a cheap hand brush during the edging process to drag across the surface horizontally in order to get a non-slip finish. I had to pick out some of the loose bristle hairs to ensure they would not fall out during the brushing process. I wet the brush before and in-between brushes to get rid of the cement build-up. This process also helped me hide some of my trowel imperfections.

Curing

Quickcrete recommends waiting 4-8 hours before exposing to rain. Well, of course, an unpredicted storm rolls through just befor the 4 hour mark, so I had to quickly cover the slab with a tarp until it blew over. After that, I began giving it a light watering every 4-ish hours to keep it from drying out too quickly. I kept up that routine for the first 7 days after pouring to help it achieve maximum strength.

Because of the thickness of the slab, I gave it a full 48 hours before removing the forms. They came off surprisingly easily with a few taps of a hammer after removing the stakes. I read that concrete contracts a bit while curing, which, I’m sure, helped. With the edges exposed, it had more surface area to dry.

Sealing

About 30 days after the initial pour, I applied some concrete sealant to ensure it was fully cured and dry. I selected a water-based, penetrating, Siliconate-based sealant for this project. These products are not cheap, so I felt lucky that I found a 16 oz sample-size container of Foundation Armor SC-25 online. I knew my small project would not need much to cover it, so did not want to buy a larger size only to have it sit in the can, unused after the project was complete.

I used a half-length roller-brush to apply in 2 coats. Application was quick and easy and should last a lifetime. It dries quickly to a natural finish, which was the look I was going for.

After the sealant was dry, I filled in the gap between the sod and the concrete to promote good water drainage.

Conclusion

30 days after pouring and the project is finally done. It’s a great, functional addition to my workshop-shed and will allow me to more easily move carts in and out. I’ve got some plans for some heavy equipment, so couldn’t even consider buying that until this project was done.

I learned a lot during this project, and have assembled yet another set of specialized tools that I may never use again. Some key lessons learned:

Careful when pouring wet concrete – if it splashes on your siding, wash it immediately
Wash tools after each use – don’t let a film build up
Do the finishing in phases starting immediately after the pour is done – don’t wait too long.
Spend more time on the finishing to really smooth the surface.
Prepare for extended care up to 7 days after the pour to achieve maximum strength
Learn the difference between “square” and “cubic” feet!