Home › Basement Waterproofing
Basement Waterproofing and Drainage in Massachusetts and New Hampshire
A wet basement can be handled from the inside, by catching the water and pumping it out, or from the outside, by digging down along the foundation. Each route comes with its own rules, from Dig Safe to where the water is allowed to go. Call (978) 800-2819 or send the form. A person reads every request and replies with what happens next.
- Free for homeowners
- Contractors screened first
- State rules explained
Ask About Basement Service in Your Area
Tell us where the water shows up and when. A person reads it and replies with what happens next.
Please add your name, a 10-digit phone number and a valid email.
Your request didn't go through on our end. Please call (978) 800-2819 so it isn't lost.
Too many requests have come from this connection in a short time. Please call (978) 800-2819 and we'll take it from there.
We couldn't finish the spam check. Wait a moment and send it again, or call (978) 800-2819.
Inside, outside or both
Two ways to keep water out, and what each one touches
Inside the basement. Interior systems collect water that reaches the foundation and send it to a sump, where a pump lifts it out of the house. The question that follows is where the pump discharges: neither state allows sump water into the sanitary sewer, and your town decides what is allowed instead. The sump pump page covers it.
Outside the foundation. Exterior work means excavating down along the wall, and in both states the excavator has to premark the area and notify Dig Safe at least 72 hours ahead, not counting weekends and legal holidays; New Hampshire's rule applies within 100 feet of an underground facility and calls for white markings (M.G.L. c.82 §40A, RSA 374:51). Dig Safe's members mark only their own lines; private lines are the owner's responsibility (Dig Safe FAQ).
Around the house. Massachusetts' residential code says lots "shall be graded to drain surface water away from foundation walls," with a 6-inch fall in the first 10 feet, and that backfill against a foundation must be free-draining and compacted in lifts of no more than 12 inches (780 CMR R401.3, R404.1.7). A good contractor will look at the ground outside as well as the wall inside.
While you wait. EPA says the key to mold control is moisture control, and that water-damaged areas and items should be dried within 24 to 48 hours (EPA mold guide).
Massachusetts
Waterproofing a Massachusetts basement
The contractor and the contract. Massachusetts defines residential contracting as the repair, alteration or improvement of an existing owner-occupied home of one to four units (M.G.L. c.142A §1); look up a company on the HIC contractor search. Agreements over $1,000 must be in writing with the registration number, dates, work, price and payment schedule, and the deposit is capped at one-third of the price or the cost of special-order materials, whichever is greater (c.142A §2).
Permits. A permit is required to alter or repair a structure, with ordinary repairs excepted (780 CMR R105). Ask your building department how it treats your job before work starts.
Drain pipes and plumbing. The state plumbing code covers piping connected with sanitary or storm drainage, but leaves out perimeter or sub-soil drains that don't discharge to a storm or sanitary drainage system; that exemption applies to pipes only, not to fixtures or appliances connected to them (248 CMR 10.03). Any discharge to ground or surface water must meet local, state and federal standards (248 CMR 10.02).
Not into the sewer. MassDEP counts sump pumps connected to the sewer as inflow and says local sewer regulations must prohibit inflow connections (MassDEP infiltration and inflow).
Flood zones. Check your address on FEMA's Flood Map Service Center; FEMA says nearly 25 percent of flood insurance claims come from outside high-risk zones (FEMA).
New Hampshire
Waterproofing a New Hampshire basement
The contractor and the contract. The Attorney General's office says, "In New Hampshire, contractors do not need to be licensed," and advises a written contract with the scope, materials, total price and payment schedule before any work or payment, plus references and proof of insurance (NH Attorney General). On contracts over $5,000, the contractor must give you written notice of its right to try to resolve alleged defects before you can sue, under the residential construction defects law (RSA 359-G).
Permits. Building permits come from your town, and local codes stricter than the state's stay in force (RSA 155-A:2).
Drain pipes and plumbing. State law counts piping connected with storm drainage within or next to a building as plumbing, up to the first fitting past the foundation wall or 5 feet from the building (RSA 153:27).
Not into the sewer. Exterior or interior foundation drains and sump pumps "shall not be directly or indirectly connected to a public sewer" (Env-Wq 704.20). Your town or sewer utility says where the water may go.
Waterfront lots. In the protected shoreland, within 250 feet of the reference line of public waters, construction, excavation or filling needs an NHDES shoreland permit; projects with no impact on water quality that follow NHDES rules may qualify for a permit by notification (<a href="https://www.des.nh.gov/protected-shoreland-faq">NHDES shoreland FAQ</a>,RSA 483-B:5-b).
New Hampshire basement rules and the towns we cover.
Last verified November 2026. New England Basement Pros is a referral service. We don't dig, drain or file permits.
FAQ
Basement waterproofing questions
Is it better to waterproof from the inside or the outside?
It depends on where the water comes in, the foundation, and what is around the house, so ask each contractor to explain why it recommends one approach. Keep in mind that outside work means excavating, which needs a Dig Safe ticket before anyone digs, and that an inside drain usually leads to a sump, which raises the question of where that water may go.
Who calls Dig Safe, me or the contractor?
In Massachusetts, Dig Safe recommends that the contractor make the call when one is hired, and the excavator has to premark the area and give at least 72 hours' notice, not counting weekends and legal holidays. In New Hampshire, excavation within 100 feet of an underground facility needs the same 72 hours' notice, and the excavator must white-mark the dig area. Either way, ask the contractor to confirm the ticket before work starts.
Can the drain water go into my sewer line?
No. MassDEP says local sewer regulations must prohibit sump pump and other inflow connections to the sewer, and New Hampshire's rules say foundation drains and sump pumps shall not be connected to a public sewer. Where the water may go instead is set by your town or sewer utility.
Will flood insurance pay to dry out a finished basement?
FEMA says flood insurance does not cover basement improvements such as finished walls, floors and ceilings, or most belongings kept in a basement. Building coverage there includes items such as furnaces, water heaters, sump pumps and foundation elements.
What does it cost me to use New England Basement Pros?
Nothing. The request and the referral are free; the contractor prices the work.
Other jobs