In most of Texas, a hard freeze shows up only a few times a winter. That is why it catches so many buildings off guard.
When Winter Storm Uri hit Texas in February 2021, burst pipes were one of the biggest sources of damage. Insured losses from the storm were estimated at more than $10 billion, and commercial claims averaged over $30,000, about twice the average home claim. Smaller businesses and schools took the hardest hit.
If you manage a warehouse, office, school, clinic, or retail space, this guide is for you.It covers where pipes freeze first, what to do before a cold front, what to do if the heat goes out, and how to thaw a pipe safely.
| The Short Answer
To prevent frozen pipes in a commercial building, keep every area with water lines at 55°F or warmer, keep fire sprinkler areas at 40°F or warmer, insulate pipes in unheated spaces, and seal drafts near pipes. Have backup heat ready for the rooms that get cold first. Most freeze damage happens in places nobody checks, like loading docks, sprinkler rooms and empty suites. |
At What Temperature Do Pipes Freeze?
Water freezes at 32°F, but a pipe doesn’t freeze the moment the outdoor temperature hits 32°F. It depends on where the pipe runs, how much insulation it has, and how long the cold lasts.
Field tests by the Building Research Council at the University of Illinois found that uninsulated pipes in an unheated attic began to freeze when the outdoor temperature dropped to 20°F or below. Plumbers in southern states report the same pattern: burst pipe calls pick up when temperatures fall into the teens.
Two things raise the risk:
- Wind: Cold air coming through gaps in walls, around doors and through vents can freeze a pipe faster than the thermometer suggests.
- Time: A few hours near 25°F is a risk. A night in the teens is a bigger one. Several days below freezing, like during Uri, is when pipes across a building start to fail.
Wet-pipe sprinkler systems and spaces containing water-filled sprinkler components need freeze protection. In many applications, fire-protection guidance uses 40°F as a minimum temperature threshold, but requirements depend on the system design and application fire code. A licensed fire-protection contractor should confirm the correct winterization approach for your building.
Why Frozen Pipes Burst
A pipe usually doesn’t burst where the ice forms. The ice blocks the pipe, and water pressure builds up between the ice and a closed faucet or valve. That pressure splits the pipe, often in a spot that looks fine. You may not see the damage until the ice melts and water starts pouring out.
Why Texas Buildings are at Risk
Buildings in colder states are designed with freezing temperatures in mind. Many Texas buildings aren’t designed for that.
- Pipes Run Through Cold Spaces: Water lines often go through attics, above drop ceilings and inside exterior walls. That works in July. In a freeze, those pipes have little protection.
- Freezes are Rare, so Prep Gets Skipped: When a building goes two or three winters without a hard freeze, insulation, shut-off labels and backup plans tend to slip.
- Heating Systems are Built for Mild Winters: A system that performs adequately during a 40°F night may struggle to maintain indoor temperatures.
- Power and Heat can Fail Together: During Uri, many buildings lost electricity, which meant they lost heat at the same time.
Where Pipes Freeze First in a Commercial Building
Start with these spots. They’re the places that freeze first in most commercial buildings.
| Area | Why it Freezes | What to Do |
|---|---|---|
| Loading Docks and Shipping Areas | Large doors open all day, and little or no heat | Keep doors closed during a freeze and add warehouse heating near pipes |
| Fire Sprinkler Risers, Valve Rooms, or Fire Pump Rooms | Often unheated or on an outside wall | Keep at 40°F or warmer and check daily during cold weather |
| Restrooms and Break Rooms on Exterior Walls | Pipes run inside cold walls | Open sink cabinets where appropriate so warm air can reach piping. Drip faucets only when site conditions and local water guidance support it. |
| Attics and Space Above Drop Ceilings | No heat, and many Texas buildings route water lines here | Insulate pipes, seal gaps and check during a freeze |
| Empty or Vacant Suites | Heat gets turned down or off | Keep the thermostat at 55°F or higher |
| Entry Vestibules and Stairwells | Cold air rushes in every time a door opens | Check pipes and sprinkler heads in these areas |
| Outdoor lines: Backflow Preventers, Hose Bibs, and irrigation | Fully exposed to the weather | Drain, shut off or cover with insulated covers before the first freeze |
| Mechanical Rooms | Outside air comes in through vents and louvers | Have your HVAC contractor review outside-air dampers, louvers, and infiltration paths before the freeze. Don’t close required ventilation or combustion-air openings without professional review. |
Before the First Cold Front: Your Pre-Freeze Checklist
Start going through this checklist in October or November, while the weather is mild and contractors have open schedules.
- Walk the Building with a Floor Plan: Mark every spot where water lines run through unheated or exterior spaces. Use the table above as your guide.
- Find and Label Your Shut-Off Valves: Know where the main water shut-off and any zone shut-offs are. Make sure more than one person knows their locations and has access to them.
- Insulate Exposed Pipes: Foam pipe sleeves are relatively inexpensive and simple to install in attics, docks and exterior walls. For pipes that stay cold, ask a plumber about heat tape.
- Seal Gaps Near Pipes: Close openings around pipe penetrations, vents, attic hatches and dock door seals.
- Service Your Heating System: Have your HVAC contractor check the heating side before winter. Our guide on how to prepare your HVAC system for winter has a simple checklist.
- Set a Thermostat Floor: The Insurance Institute for Business and Home Safety (IBHS) recommends never setting the thermostat below 55°F, including nights, weekends and empty suites.
- Have Your Fire Sprinkler System Checked: A licensed fire protection contractor should confirm sprinkler areas stay at 40°F or above and that dry or antifreeze systems are ready for winter.
- Drain and Shut Off Outdoor Lines: That includes irrigation, hose bibs and fountains. Cover backflow preventers.
- Add Low-Temperature Alerts: Wireless sensors that text you when a room drops below 40°F are relatively inexpensive and give you time to act.
- Line Up Backup Heat Now: Decide which rooms need temporary heat if your heating or power fails, and talk to a rental company before a storm. Once a storm is on the way, rental equipment gets hard to find. Our emergency heating rentals page shows what we can deliver.
When a Freeze is 48 Hours Away
Once a hard freeze appears in the forecast, work through this list:
- Confirm heat is on in every zone, including vacant spaces. Raise setpoints a few degrees if you can.
- Open cabinet doors under sinks on exterior walls so warm air can reach the pipes.
- Where permitted and appropriate, allow vulnerable faucets to drip slowly to reduce pressure buildup and keep some water moving. Follow local utility guidance during prolonged freezes, especially if water systems are under strain.
- Keep dock doors and roll-up doors closed as much as possible.
- Place temporary heaters in the cold spots you marked during your walk-through.
- Set a schedule for staff to check high-risk areas, including overnight and on weekends.
- Post shut-off locations and phone numbers for your plumber, fire sprinkler contractor and heater rental company where your team can see them.
When the Heat Goes Out: Using Temporary Heating Safely
If your heating system fails or the power goes out, response time becomes critical. In a building with pipes in exterior walls and ceilings, you may have hours, not days, before pipes freeze. Temporary heat buys you that time.
These are the three types of heaters we rent most often for freeze protection:
| Heater Type | How it Works | Best For |
|---|---|---|
| Electric Heaters | Plug into building power. No fumes and no venting. Our units range from 50,000 BTU to over 200,000 BTU. | Offices, restrooms, sprinkler rooms and other indoor spaces with power available |
| Portable Heat Pumps | Electric units that move heat instead of making it, so they can deliver more heating output per unit of electricity than resistance heat under suitable operating conditions; actual performance depends on ambient temperature and the specific unit. | Offices, clinics and spaces that need steady heat for several days |
| Indirect-Fired Heaters | Burn propane, natural gas or diesel outside the building and send clean and warm air inside through a duct. The exhaust stays outside. | Warehouses, docks, large open areas and buildings without enough electrical capacity |
Safety Rules for Temporary Heating
- Use only heaters rated for indoor use inside the building. Never use a grill, camp stove or unvented fuel heater indoors. Carbon monoxide builds up fast, and you can’t see or smell it.
- Keep heaters at least 3ft from boxes, paper and anything else that can burn, and follow the clearances on the heater label.
- Put carbon monoxide alarms in any area near fuel-fired equipment.
- Check that your circuits can handle electric heaters. Larger units need a specific outlet, and we will confirm this with you before delivery.
- Fuel-fired heaters still need a small amount of power to run their fans. If the grid is down, ask us about your options.
For more on this, see our electric heater safety tips.
How Many Heaters will You Need?
It depends on the size of the space, how cold it gets outside and how well the room holds heat. Share the room dimensions, ceiling heights, and high-risk areas with our team. If you want to understand the math first, our guide on what size heater you need explains how BTUs work.
Signs Your Pipes Have Frozen
- A faucet gives little or no water, or a toilet doesn’t refill.
- You can see frost on the outside of a pipe.
- A section of wall or ceiling feels much colder than the area around it.
- You notice odd smells coming from drains.
- A pipe looks bulged, or you see new water stains on ceilings or walls.
If the water has stopped but nothing is leaking yet, you may still have time to thaw the pipe before it bursts.
How to Thaw a Frozen Pipe Safely
- Open the Faucet the Pipe Feeds: As the ice melts, water needs somewhere to go, and running water helps melt the rest.
- Warm the Pipe Slowly: Start near the faucet and work back toward the frozen section. Use controlled and manufacturer-approved electric heat such as a hair dryer or heating pad where accessible. If using a portable electric heater to warm the surrounding area, maintain required clearances and never place it directly against piping, walls, insulation, or combustible materials.
- Never Use a Torch, a Propane Heater or Any Open Flame on a Pipe: It can start a fire inside the wall.
- Keep the Heat on Until Full Water Pressure Returns: Then check other faucets. If one pipe froze, others may also be frozen.
- Call a Licensed Plumber: If you can’t find the frozen section, can’t reach it, or it’s inside a wall or ceiling.
If a Pipe Bursts
Shut off the water at the main right away.If water is near electrical outlets or equipment, shut off power to the affected area only if it can be done safely. Call your plumber, then start drying. The EPA recommends drying wet materials quickly, often within 24-48 hours, because mold can begin growing when moisture and other favorable conditions persist. Commercial dehumidifiers and air scrubbers speed this up.
Put Your Freeze Plan on One Page
A freeze plan is only effective when responsibilities are clearly assigned. Here is a simple way to split it up:
| Who | What They Own | When |
|---|---|---|
| Facility Manager | Owns the plan, calls vendors, and decides when to shut off water | Before winter and during every freeze |
| Maintenance Lead | Walk-through, insulation, sensors, faucet drips, and heater placement | October to November, then every few hours during a freeze |
| Security or Night Staff | Checks high-risk rooms on rounds and reports cold spots | Nights and weekends during a freeze |
| Vendors: Plumber, Fire Sprinkler Contractor, Heater Rental | On-call support | Numbers saved in phones before winter |
Print it, and post it in the maintenance office, and walk through it with your team at least once before December.
How Preferred Climate Solutions Can Help
We are a Texas-owned company, and we have been renting heating and cooling equipment since 2007. When a freeze hits, we deliver and set up temporary heat for offices, warehouses, schools, clinics and job sites from our locations in Houston, Dallas–Fort Worth, Austin, San Antonio and Oklahoma City.
- 24/7 emergency dispatch, including nights and weekends.
- Help choosing the right heater and the right size for each space, from office heaters to large warehouse units.
- Delivery, setup and pickup, so your team can focus on the building.
When a building’s heating system cannot maintain safe indoor temperatures during a cold snap, commercial heater rental may help restore temporary heat while permanent repairs are arranged.
The best time to arrange backup heating is before demand increases ahead of a major freeze. To reserve heaters for your building, or if your heat has already failed, call 844.738.9736 or request a quote. You can also browse our full range of heater rentals.
Frequently Asked Questions
At what temperature should I worry about pipes freezing?
Start preparing when lows are forecast at 28°F or below. The National Weather Service uses that number for hard freeze warnings. Pipes in attics, exterior walls and unheated areas are at serious risk once it drops to about 20°F.
What temperature should I keep an empty building at in winter?
Keep every area with water lines at 55°F or higher, and fire sprinkler areas at 40°F or higher. Don’t turn the heat off in vacant suites.
Should I drip faucets in a commercial building?
Yes, For cold-water faucets on exterior walls or in cold areas during a hard freeze. A slow drip is enough. During long freezes, some Texas cities have asked people to limit dripping to protect water pressure, so follow local guidance.
Can a space heater keep pipes from freezing?
Yes. A heater rated for indoor use, and placed safely near the cold area, can keep pipes above freezing. For large areas like docks and warehouses, you will need bigger units such as indirect-fired heaters.
How fast can you deliver heaters during a freeze?
In most cases we deliver the same day, and our dispatch runs 24/7. Demand spikes right before a storm, so reserving early is the safest move.