Category: Home Improvement

In this post, I’ll explain step by step how my HVAC guy replaced an old rooftop HVAC stand with a modern HVAC curb.

I had this done due to water leaking into the building from multiple places below the HVAC unit. The entire process took 6 hours nonstop. These steps can also be used to replace an old HVAC unit.

Below are before and after pictures showing the difference.

BEFORE

In the following photo, you’ll see the rusted metal stand below the HVAC unit. That stand was from 1978. The HVAC unit was replaced in 2025, but the HVAC contractor was cheap and didn’t replace the stand with a modern curb. Instead, since the new HVAC unit was too large for the stand, he strapped two pressure-treated 2x4s to the stand using a strip of thin metal.

In the photo below, you’ll also see the old “elbow” at the back of the HVAC unit where the air flows into the ducting in the attic and into the building. The elbow is from 1978. Had the HVAC contractor replaced the stand with a modern curb (shown in the “after” photo below), the elbow would be removed and air from the HVAC unit would flow straight down from below the unit.

AFTER

In the following photo, you’ll see the old stand was replaced with a “curb”, which is an enclosed stand. Also, the elbow was removed and the air inlet/outlet on the back of the HVAC unit was closed off with sheet metal because the air now flowed into the building from below the HVAC unit. You’ll also notice the electrical wires (power and thermostat) come out of the roof below the HVAC unit rather than next to it.

If you’re replacing a rooftop HVAC unit, you won’t need to follow all of the steps here.

Note: Most of the screenshots below were taken from this corresponding video.

Order a curb that is designed for the HVAC unit you have. A curb looks similar to the picture below.

Disconnect everything from the HVAC unit so it can be lifted using a crane and replaced with the same or a newer one.

Have a crane operator come to lift the curb onto the roof.

Connect the 4 rope hooks to the 4 holes in the metal base of the HVAC unit. Instruct the crane operator to life the HVAC unit and place it somewhere else.

In my case, since we weren’t replacing the HVAC unit itself, we just placed the HVAC unit on another area of the roof.

With the HVAC unit out of the way, we can see the old elbow and ducting that goes into the attic. The left duct is for air to return to the HVAC unit and the right duct is for conditioned air to flow into the building.

Remove the elbow. You may need a pry bar to lift some shingles and a utility knife to cut some sealant connecting the elbow to the shingles.

Here’s how the opening in the roof looks with the elbow removed.

After dry-fitting the curb on the roof where you want it to go, mark along the inside perimeter and then cut the shingles along the left and right edges of the perimeter. If using a circular saw, adjust the blade cutting depth to avoid cutting deeper than the shingles.

Using a pry bar, a row or two of shingles at the top edge and a bit of shingles on the left and right edges.

Drill a hole in the roof inside the curb so that the electrical cables can come up through the roof from below the HVAC unit rather than next to the unit.

Turn off the circuit breaker to the HVAC unit and check for any voltage. My Lennox 2.5 ton package HVAC unit had two hot wires, red and black, each at 120V, for a total of 240V. The green wire was for ground.

Remove the line cable, which supplies electrical power from the circuit breaker box, from the HVAC electrical box.

Since the Romex line cable will be moved to come up through the roof from under the HVAC unit, we removed the conduit.

We then pushed the Romex back into the attic so we could push it through the hole in the roof we made earlier.

Then go into the attic so you can push the Romex cable through the new hole in the roof.

Slide the top half of each side of the curb under the shingles and move the curb into its final position.

You may need to remove some nails holding some shingles down.

Place a magnetic torpedo level on one side of the curb, then lift the front of the curb up until the level shows it is level. This is so the HVAC unit will sit level on the curb rather than angled following the slope of the roof.

When it’s level, drill a self-tapping screw for metal from the outer side of the curb through the inner side of the curb to hold the outer side in place.

Drill screws in multiple places to ensure the top of the curb remains level and can support the weight of the HVAC unit.

Install the 4 brackets that came with the curb – 2 on the front and one on each side.

Drill a 3/4″ diameter hole in the front of the curb for the electrical Romex cable and the t-stat (thermostat) cable to go through.

We needed some sheet metal to connect some ducts and cover some openings. It’s much cheaper to buy a roll at a dedicated HVAC store than the big-box stores like Home Depot, which only sell small sheets. However, some HVAC stores only allow licensed contractors to buy from them.

The sheet metal roll is held in place using a long zip tie.

When going up and down the ladder, make sure to strap the ladder to the building, like an eye hook in the eaves, to keep the ladder from moving. Some city inspectors require this when they come for an inspection.

Cut pieces of sheet metal to connect the duct in the attic to the curb.

Use a flashing folding tool to fold some edges of the sheet metal.

Position the cut sheet metal to connect the duct to the curb.

Then screw the cut sheet metal to the curb.

Repeat until you’ve connected the duct in the attic to the curb.

Apply HVAC foil sealer duct tape at the edges of the sheet metal connections.

If it helps, you can reuse old duct parts to connect the duct in the attic to the curb. In the following photo, the left opening is where air flows into the building. The right opening is where air flows from the building back into the HVAC unit.

Connecting the duct to the curb can be tricky because there may not be enough slack in flexible ducts and you are sometimes working in tight spaces.

In this case, the contractor had to create a short circular duct to extend the flexible duct that was in the attic.

He inserted the duct at an angle since the flexible duct in the attic came in at an angle.

Then, he screwed in the extension piece using self-tapping sheet metal screws.

Then he screwed the flexible duct to the duct extension he just created.

And he applied HVAC tape to all duct and curb connections.

He also covered all gaps with HVAC tape. For big gaps, as shown below, the tape will serve as backing for the HVAC sealant (Pookie).

Apply HVAC sealant (Pookie) to all seams and connections. When dry, this sealant becomes very hard.

Stick the electrical line cable and load wires (red, black, and green) through the hole previously made in the curb. The load wires connect from the wires in the line cable to the terminals in the HVAC unit.

Insert a 3/4″ plastic bushing in the hole in the metal curb to prevent the wires from getting cut if they slide against the sharp metal hole in the curb.

Stick the wires through the hole in the electrical box.

Screw the box to the curb.

Since both the black and white wires in the line cable are hot (120V), the white wire must be colored black to indicate it is hot. You can cover a portion of the white cable sleeve with black electrical tape.

Connect the wires to the appropriate terminals in the electrical junction box.

Screw the plastic cover over the terminals.

Insert the circuit breaker.

Close the box door.

Optionally lock the door by inserting a lock through the hole.

Tape the ends of the load wires and the thermostat wires together to make it easier to access them when the HVAC unit is lowered onto the curb.

Screw the base of the curb into the roof at various places.

Drill a 3/4″ hole at the bottom of the HVAC unit near where the power and thermostat wires will connect to the unit.

Since the previous HVAC contractor connected the unit to the elbow at the back of the unit, we had to remove the tape and sealant that remained after disconnecting the elbow from the unit.

The contractor unscrewed and removed the two panels at the bottom of the HVAC unit since airflow will flow through the bottom rather than the back.

He then measured the openings so he could create some custom panels using sheet metal.

The crane returned to lift the HVAC unit and lower it onto the new curb. The contractor inserted the 4 hooks into the 4 holes at the base of the unit.

The contractor pulled the load and thermostat wire through the hole he made in the base of the HVAC unit.

The unit was then lowered onto the curb such that the base would sit on the 4 brackets around the top of the curb.

The contractor routed the wires to where they need to be connected.

He connected the load wires (black, red, and green) to the appropriate terminals.

He connected the thermostat wires to the corresponding color-coded wires in the HVAC unit.

He then connected the gas line to the unit.

He applied PVC glue to connect the drip line to the unit.

He put HVAC tape to close the gap between the openings at the bottom of the unit and the duct openings in the roof.

He brushed on some HVAC sealant (Pookie) over the tape.

He cut some sheet metal to cover the two openings at the back of the unit.

He folded the 4 corners of the sheet to fit over the lip of the openings at the back of the unit.

And he screwed the panels in place

He put HVAC tape around the panels, but he didn’t apply HVAC sealant (Pookie) over the tape so that maintenance and inspection can easily be done in the future, if needed. (Pookie dries really hard and is hard to remove)

He screwed the electrical panel back on the unit.

He put new shingles over the area where he had to remove some old shingles.

Since replacing the stand with a curb, the HVAC unit was moved up, so he had to add an extension to the old PVC drip line.

Since the old electrical line cable was moved from outside the HVAV unit to under the unit, he covered the old hole in the roof with HVAC tape, which is very sticky tape.

He applied silicone sealant over screws that could result in roof leaks.

He also applied silicone sealant around the electrical box.

The feet of the old stand were screwed into the roof. He lifted the shingles where the feet were using a pry bar.

And applied sealant in the holes beneath the top layer of shingles.

He then pressed down on the top layer of shingles so the sealant would squeeze out of the holes.

He smeared the sealant to completely cover the holes.

He also applied sealant over the tape that covered the hole where the electrical Romex line cable came out.

And here’s how everything looked when he was done.

He only needed the shingles to cover the top half of both sides of the curb because the lip at the perimeter of the curb would force water to run down the roof rather than sideways.

Some home improvement projects can produce a lot of dust, like when dealing with drywall, concrete, and mortar. Additionally, when you have contractors coming and going into your home, it’s nice to have a temporary partition for privacy. You can buy a plastic dust containment door at Home Depot for $30, but that’s expensive for a piece of plastic, and it only covers a 3′ x 7′ door opening. One option for covering a large space to both block dust and create privacy is by hanging blackout curtains on a sliding track, as shown below.

• Blackout curtains on Amazon (2-pack for $20, but now the price is $108)
• Ceiling curtain track (2-pack for $60)

Note: if you don’t need to slide open the temporary wall, you can screw some 2×4 pieces of wood to the ceiling and then screw or staple the curtain to the 2×4 wood. You can also replace the curtains with thin (or thick) plastic or canvas drop cloth. In my case, I wanted the ability to easily slide the curtain wall open when the contractors weren’t working.

I first bought a lightweight shower curtain, but it was more expensive than the blackout curtains, and it filtered light, so anyone could see through both sides.

The curtain track just screws into your ceiling, either into joists or just drywall, using anchors.

You can also adjust the length of the track.

I went with two tracks and two curtains. Where the curtains meet in the middle, I had one curtain partially hang on the hooks of the other track for about 1 foot of overlap. This minimized any gaps in the middle for dust to get through.

CAUTION: While you might not think dust will get very far, you’d be surprised how wrong you are. Before I put up these curtains, dust managed to make it all the way to my living room, as I saw a thin film of it on my laptop cover. Also, there was a thin film of dust on the kitchen floor as well. While cleaning large flat surfaces like floors is easy, it’s not when dust gets into many nooks and crannies or in rugs.

The next time you need to do home improvement that could generate a lot of dust, or if you just need a temporary privacy wall, the ceiling track and curtain solution above may be just what you need, unless you want to spend all day removing dust everywhere.

Most of the time, stud finders are sufficient to tell you what’s behind some drywall since most drywall just has 2×4 wood studs behind it. But what if you’re still unsure of what’s really behind some drywall. Here’s a simple way to visually peek behind drywall without making a mess or giving yourself a lot of work.

1. Get a borescope inspection camera

I have this one and I think it’s good.

2, Drill a one-inch hole in your drywall.

You can use a 1″ spade bit.

3. Stick your inspection camera through the hole

You should now be able to see what’s behind the wall.

4. Prepare to patch the hole

Get some joint compound and a joint knife.

5. Spread the joint compound over the hole

Some compound may ooze out the back. That’s okay.

6. Wait 24 hours and add more compound

7. If necessary, repeat step 6 again

8. Sand, (texturize?), and paint

Note: When the joint compound dries, it will become very hard, and you can probably stick a nail or screw in it to hang something. For a one-inch hole, to keep things simple, I didn’t use any joint tape, and this method worked just fine without it.

One of the concrete slabs (7′ x 8′ x 3″) by my driveway was cracked and sunken. The previous owner created the slab and didn’t include rebar. I paid someone $75 to break the slab into small chucks.

He used my jackhammer to break the slab, which you can buy on Amazon for $140.

I then rented a box truck from Home Depot for $29 / 75 minutes and took the concrete to GreenWaste. The cost to dump the concrete was $54.

Here’s how the space looked after removing the concrete. I would need about 0.5 cubic yards of concrete.

If I wanted to pay a concrete supplier like EZ-MIX CONCRETE to deliver pre-mixed concrete by truck, it would have cost me about $600 because they charge a minimum of 2 cubic yards.

I posted an RFQ on Yelp and Thumbtack and got the following quotes for both labor and materials:

• Contractor 1: $1200
• Contractor 2: $950
• Contractor 3: $800

Contractor 3 happened to live 2 blocks from me. I chose him because he showed me the sample concrete work he had done, which looked very good, and his quote was the most reasonable. He went to Home Depot to buy rebar and about 35 bags of 60 lb concrete.

According to Home Depot, the concrete cost would be about $160 + tax, which includes 10% extra concrete.

There were 3 workers who came at 7 AM to start the project. First, they cut the rebar using an angle grinder and laid it down.

They then mixed the concrete with water in a wheelbarrow by hand using small shovels.

They should have just used an electric mixer to make mixing easy.

They then used a rake and a long bar to push and even out the wet concrete.

They then used a rough float to even out the surface.

They then used a large float to smoothen the surface.

and an edger to create a beveled edge.

This is how the surface looked when the concrete was still wet.

After waiting 1 to 1.5 hours, they came back and continued to smooth the surface, first using a rough trowel

and then using a finishing trowel.

Then, they came back about 30 minutes later to create a brushed texture for traction using a concrete broom.

As you can see, the surface came out very nice.

Cypress trees are fast-growing, tall, narrow, evergreen trees.

They look nice, but if they grow too tall and it’s very windy, they can become a liability if they fall and damage your or someone else’s property. Unless they’re located far from where they can cause damage, the safe thing to do is to cut them short. If you wait too long, cutting the top off can be difficult and expensive. For example, in the video below, you can see one person on a ladder cutting the tree trunk on one side and two people on the ground holding and pulling a rope tied to the top part of the tree to ensure the tree falls away from damaging anything.

Cutting tall Cypress trees can be expensive. For that reason, it’s best to cut these trees before they get too tall. For example, I have 6 Cypress trees in my backyard. I was able to cut them so they were about 10′ tall. I rented a 14′ A-frame ladder from Home Depot and strapped it to the roof rack of my car using heavy-duty ratchet straps.

I first pruned some branches using the Ryobi 18V Cordless, Brushless Pruner.

I then used a Ryobi 18V Brushless, Cordless, Compact, One-Handed Reciprocating Saw to cut the trunk at around 10′ from the ground.

If the trunk was too difficult to cut with the sawzall, I’d use my Ryobi 40V HP Brushless 14 in. Battery Chainsaw. Cutting the trunk with this chainsaw was easy but a bit dangerous as you had to hold it with two hands due to its size and weight, unlike the one-handed compact sawzall.

Ryobi sells a compact 18V battery-powered chainsaw, which may be small and light enough to use with just one hand.

To be safe, you can have someone hold the ladder while you’re up on it or strap the ladder to the tree or a nearby fence to prevent it from falling over.

To eliminate maintenance and water costs, I replaced my front yard with rocks and 6 Cypress trees. The front yard slopes away from the house toward the street. Since I don’t need to water any plants or trees (the Cypress trees can survive off of rainwater in the Winter), I put down 20-mil thick pond liner. Where two pieces of pond liner meet, I overlap them by 12 inches.

Along the perimeter, I screwed 2x4s into the sides of the concrete using concrete screws. I stapled the pond liner to the 2x4s along the perimeter and then screwed 1.5″ x 1.5″ brown drip edge to prevent weeds from sneaking their way up along the crevices.

If one of your edges is not a standard concrete slab, you may install a short retaining wall. In my case, I made a wall using 12″ wide pressure-treated wood that I held in place using metal stakes. I used brown deck screws that were designed for exterior use to minimize rust and corrosion.

I should have placed the pond liner under the wood before securing the wood in place. Since I didn’t do that, I stapled the pond liner to the side of the wood and then screwed thin wood wrapped in brown plastic (bender board) over the pond liner and into the wood. That should prevent weeds from growing between the wood retaining wall and the pond liner.

As a real estate investor, I’m often needing to know what’s behind some drywall. I normally use a stud finder, but after removing a bunch of drywall, I sometimes find pipes, which, unlike electrical cables, are difficult to move, so I end up wasting my or my contractor’s time patching a wall back up. So, I bought the Walabot DIY 2, which claims to be able to detect wood and metal studs, plastic and metal pipes, and wires behind drywall up to 5/8″ thick and 4″ deep.

I put this to the test and compared it to my Franklin ProSensor M150, which can detect wood and metal studs as well as live wires up to 1.5″ deep.

I tested both sensors on an actual wall with pipes and live wires as well as a test wall.

My test wall below has, from left to right,

• 2×4 stud
• 15A Romex wire (non-live)
• Pressure-treated 2×4 stud
• 2×4 stud
• 2″ black ABS drain pipe
• Metal copper pipe
• 2×4 stud

The Walabot DIY2 detected all items, but it couldn’t differentiate between a wire and a pipe. Also, the Walabot got a bit confused by the 2 touching studs in the middle because of the small gap between the studs. The Franklin only detected the wood studs, but it detected them very well, including the two touching studs.

On an actual wall with wood studs, pipes and live wires, the Walabot performed the same, and it couldn’t differentiate between pipes and wires. The Franklin sensor, however, was able to detect live wires. The lightning symbols lit up yellow when a live wire was detected, as shown below.

Conclusion

It looks like both detectors are needed to see what’s behind your walls. I’d use them as follows:

1. Use the Walabot first to mark all wood/metal studs, and pipes/wires.
2. Use the Franklin to confirm the location of the wood/metal studs and to determine whether the pipe/wire detections by the Walabot are live wires or pipes. If the Franklin detects live wires, then that’s what they are. If the Franklin doesn’t detect anything where the Walabot detected a pipe/wire, then there’s a pipe there.

In America, many people use their garages as storage rooms rather than what they were intended for (parking vehicles). I do the same, but I also use my garage as a home gym. Along the side walls are 5-tier shelf racks with wheels and on each shelf there are 3 transparent plastic containers.

• TRINITY EcoStorage 5-tier Wire Shelving Rack 48″ x 24″ x 72″ NSF, Includes Wheels
• SAMLA Box, clear, 22 ½x15 ¼x11 “/12 gallon

If you want a lid for the bin, you can buy it separately for $3.

• SAMLA Lid for box, 12/17 gallon, clear

Having shelves with wheels makes it easy to move everything around.

But what do you do when you are renovating or remodeling your garage or if you need a temporary place to store your stuff for about 6-12 months. You can put everything in a self-storage unit, but for a 20’x20′ garage worth of stuff, you’re looking at paying hundreds of dollars a month if you are in the San Francisco Bay Area. You can buy a shed and put it in your backyard, but a large one would cost your around $1500, and you may not necessarily have the space for a large one in your backyard. Plus, you’d have to spend a lot of time assembling it, and it’s more of a permanent solution rather than a temporary one.

One low-cost option is to simply put your stuff in heavy-duty plastic storage containers with lids and stack them up in your backyard. Since they come with a lid, you wouldn’t need a shed because they are waterproof. If you’re worried strong winds could blow the lids off, just place something heavy on them, like a concrete paver.

The 27-gallon plastic bins are a good size as they’re not too big to carry and they’re not too small to fit somewhat large items.

• Project Source Commander Large 27 -Gallons ( 108 -Quarts ) Clear Heavy Duty Stackable Tote with Standard Snap Lid

The transparent kind is nice because you can see what’s inside and don’t need to necessarily label each bin. If you do want to label the bins, you can buy a label maker. This Brother P-touch PT- D610BT can print up to 1″ labels, making it easy to read them from a distance.

As of this writing, the price for a 27-gallon bin is $14, so even if you needed 35 of them, you’re only paying $500 for them, and when you’re done using them, you can easily empty the contents and stack them inside each other for future use.

UPDATE: Costco Business Center has the same 27-gallon bins for $11. Both the bin and the lid are transparent, which is even better.

If you have a lot of stuffed bins, some of which may be heavy, you don’t want to have to carry each one. For convenience, you can just buy a folding platform truck.

• FRANKLIN 19 in. x 29 in. Folding Platform Truck

For $36, it’s totally worth it. The plastic bins fit on the platform and the handle allows for comfortable pushing or pulling (I prefer pulling). When you’re done moving the bins, you can fold the handle down so the dolly doesn’t take up a lot of space.

Now, you may have some large or long items that won’t fit in those 27-gallon bins. For these items, you can either but a few larger bins, like this 75-gallon one, which comes with its own wheels.

• Project Source Commander X-large 75 -Gallons ( 300 -Quarts ) Black and Yellow Heavy Duty Rolling Stackable Tote with Standard Snap Lid

Or, you can just buy a small shed just for those items.

If you leave things exposed to the elements for a long time, they can become weathered and even break down. Thin plastic, for example, can become brittle from long exposure to the sun’s UV rays. To prevent this from happening, you can cover the bins with a heavy-duty tarp that is treated to prevent deterioration from UV rays.

If the tarp doesn’t cover the sides and you’re worried water might get in through some small gaps between the bins and their covers, you can cover the gaps with duct tape.

Or, you can buy a bigger tarp. The one picture below is 9mm thick (heavy duty) and from Harbor Freight.

But what if you have a bunch of shelving racks with uncovered bins in them? In this case, rather than disassemble the racks and buy lids for those bins, you can buy a cover designed specifically for shelving racks. There are many on Amazon with many different sizes. I bought this 72″ H x 48″ W x 18″ D one on Amazon. It’s waterproof and the zippers make it easy to open one side when you need to get something.

If you have to store a bunch of clothes, a cheaper storage option is to put the clothes in a cardboard box or a plastic tote bag, like this.

• Mainstays Heavy Duty Storage and Moving Bag, Clear, 20 Gallon

For just $5, these large, 20-gallon plastic totes are cheap and, since they’re designed for light items, like clothes, you can easily carry them without the need for a platform truck or dolly. They also come with a zipper. If you go with cardboard boxes, not only are they not waterproof, but you’d have to use tape to close them, which is extra work.

So there you have it. A cheap, easy, and organized way to temporarily store stuff in your backyard.

Most homeowners, and, surprisingly, some plumbers, only use Teflon tape around pipe threads. While this often is sufficient to prevent leaks, it is not the best practice. For more reliable results, always use a combination of Teflon tape followed by thread sealant.

One of the most popular thread sealants is RectorSeal #5.

As a real estate investor, I’ve had to replace many toilets. Normally, I do that while doing a complete renovation. The problem with many toilets is

1. the bolts to the toilet flange in the floor can get loose
2. the floor may not be perfectly level

These issues can cause a toilet to slide, rotate, and tilt.

Fixing a rocking toilet due to an uneven floor

After renovating many bathroom floors with both tile and vinyl, it’s unfortunate that despite a contractor’s best effort to create a perfectly level floor, a small imperfection could cause a toilet to not sit evenly on the floor. The easily way to fix this is by installing plastic toilet shims on the LOW side of the toilet. Make sure to install it on the LOW side as the weight of the toilet will help keep the shim in place.

Fixing a loose toilet due to loose bolts

The bolts that come with many toilets are usually the cheap kind. Sometimes, they work just fine, but depending on your toilet flange and toilet, they may easily become loose, which is what happened to me. To remedy this, I replaced the cheap toilet flange bolts with the Fluidmaster SetFast 5/16 in. x 2-1/4 in. No-Cut Brass Closet Toilet Bolt Kit. Price at $8, which is about double the cost of the cheap bolts, these bolts don’t require any cutting and they securely hold your toilet in place. Unlike some other toilet bolts that come with a small head, the bolt head the Fluidmaster bolt is thick and wide, so the bolt remains within the toilet flange slot no matter what.

When you tighten the acorn nut, the height of the threaded stud decreases automatically.

The yellow lock washer is thick, which holds the bolt in place vertically as you place the toilet over the bolts. This is way better other toilet bolt kits, which either don’t come with a lock washer, or the lock washers are thin and flimsy.