Kermit Beseke, Respondent, vs. County of Goodhue, et al., Appellants.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C8-98-489

Janet Langfield, et al.,

Respondents,

vs.

Hans Pfannkuch, et al.,

Appellants.

 Filed November 17, 1998

 Affirmed in Part, Reversed in Part, and Remanded for New Trial

Davies, Judge

 Concurring Specially, Short, Judge

Ramsey County District Court

File No. C89610740

James B. Gasperini, The Afton Law Office, P.A., 3121 South St. Croix Trail, Suite 204, Afton, MN 55001 (for respondents)

John F. Bannigan, Jr., John F. Ebner, Bannigan & Kelly, P.A., 445 Minnesota St., Suite 1750, St. Paul, MN 55101 (for appellants)

Considered and decided by Davies, Presiding Judge, Schumacher, Judge, and Short, Judge.

 U N P U B L I S H E D O P I N I O N

 DAVIES, Judge

Respondents brought this action to establish the boundary line between their property and appellants' property. The trial court established a property line based on a survey offered by respondents and created a prescriptive easement on appellants' property for respondents to maintain and repair their house. Appellants moved for amended findings and a new trial, and now appeal the order denying both. We affirm in part, reverse in part, and remand for a new trial.

 D E C I S I O N

An order denying a new trial is upheld unless there was a clear abuse of discretion by the trial court. Younggren v. Younggren, 556 N.W.2d 228, 231 (Minn. App. 1996). But a motion for a new trial must be granted where there is a lack of evidence supporting a finding. Gilbert v. Brindle, 306 Minn. 569, 570, 237 N.W.2d 83, 84-85 (1975). Additionally, a new trial motion must be granted where the only evidence on a material finding is speculative. Rudd v. Lyceum Dramatic Prods., Inc., 250 Minn. 328, 336, 85 N.W.2d 61, 66 (1957). When a new trial is granted, issues that were properly determined need not be retried. Stolp v. Reiter, 190 Minn. 382, 388, 251 N.W. 903, 905 (1933). Where the appeal is from an order denying a new trial, the reviewing court can only grant a new trial and cannot direct the result. Schimmelpfennig v. Gaedke, 223 Minn. 542, 549-50, 27 N.W.2d 416, 421 (1947). Denial of a motion for amended findings is not appealable. Minn. R. Civ. App. P. 103.03.

 I.

Respondents' house is located on lot 6, block 40, Saint Anthony Park North, Saint Paul. Appellants' house is located next door, on lot 7. Respondents initiated this action to determine the boundary line between the two lots. At trial, the parties offered competing surveys. Appellants submitted a 1923 survey that was derived from a 1911 survey. The 1911 survey found and used an iron monument located on the northwest corner of block 40, more than 600 feet from the disputed property line. The plat indicates an iron monument at that corner. Respondents' survey was a retracement of an 1898 survey that, according to the 1898 surveyor's notes, was based on wooden lot stakes. The trial court found this 1898 survey more reliable.

Saint Anthony Park North, Saint Paul, was surveyed for plat in 1885. When, as here, the deeds to the properties refer to a plat, the plat is conclusive evidence of the property lines. Dittrich v. Ubl, 216 Minn. 396, 401, 13 N.W.2d 384, 388 (1944). When determining a boundary line, the court seeks to establish a boundary consistent with the original intent of the grantor (here, the platter). Id. at 406, 13 N.W.2d at 390. The best evidence of a boundary line is evidence directly traceable to the plat. Id. at 404, 13 N.W.2d at 389.

None of the trial court's findings connected the 1898 survey to the 1885 plat, and respondents' testimonial evidence was speculative regarding the material issue of whether the 1898 survey could be traced back to the plat. The only evidence that the platter laid the wooden stakes was an expert's testimony that platters often marked out lots with such stakes. Stakes set by the original platters govern in a boundary dispute but, if such stakes are to be relied on, it must be proven that they were authoritatively set. Id. Evidence other than plat monuments is admissible only if no monument is mentioned in the plat, no monument is available, or the monument that is available is proven unreliable. Id. at 403, 13 N.W.2d at 388. Here, an iron monument on the northwest corner of block 40 was indicated in the plat. Appellants' only evidence that the monument was unreliable was that there had been construction near that corner sometime before 1911. But such speculative evidence is insufficient to support the trial court's conclusion that the 1898 survey was more reliable.

The trial court abused its discretion by not granting a new trial; its order is reversed and the matter is remanded for a new trial.

 II.

In their motion for amended findings or a new trial, appellants alleged that the trial court's conclusion that there was a prescriptive easement on lot 7 for repair and maintenance of the house on lot 6 was contrary to law. When a motion for a new trial is made on this basis, the trial court must consider whether applicable principles of law support its conclusion, even conceding everything the evidence tends to prove. In re Buck's Estate, 122 Minn. 463, 467-68, 142 N.W. 729, 731 (1913). The trial court must grant the motion if the law does not reasonably sustain its conclusion. Id.

Adverse possession (and, by analogy, a prescriptive easement) is established by actual, open, hostile, continuous, and exclusive possession for the statutory period of 15 years. Roemer v. Eversman, 304 N.W.2d 653, 653 (Minn. 1981); see also Minn. Stat. § 541.02 (1996) (15-year-period to create a prescriptive easement). Our supreme court has held that periodically passing onto adjoining urban property to maintain a house on one's own property is not sufficiently hostile and continuous to establish a prescriptive easement. Romans v. Nadler, 217 Minn. 174, 181-83, 14 N.W.2d 482, 486-87 (1944).

In Romans, respondent Romans periodically, and without permission, placed his ladder on the neighbor's lawn to paint his house and repair and maintain his windows. Id. at 176-177, 14 N.W.2d at 484. The supreme court reversed the trial court's decision to grant Romans a prescriptive easement, holding that Romans' use of the neighboring property was simply an occasional trespass that was not continuous and did not indicate hostility. Id. at 180-81, 14 N.W.2d. at 486. Here, respondents' use of the adjoining property was similar to the window washing every six months and painting every six years that the Romans court held to be too occasional and sporadic to merit a prescriptive easement. Respondents did not present sufficient evidence to establish a hostile and continuous use justifying a prescriptive easement on lot 7 for repair and maintenance of the house on lot 6. The trial court abused its discretion by denying a new trial and refusing to make a new finding regarding the propriety of that appurtenant prescriptive easement.

In contrast, the eaves and gutters of respondents' house have hung over the property line since 1888. This is long enough to establish a prescriptive easement

for the eaves to continue to hang and drip there. See Minn. Stat. § 541.02 (15-year period to create prescriptive easement); Romans, 217 Minn. at 180, 14 N.W.2d at 486 (eaves hanging over and dripping on another's property for statutory period creates prescriptive easement to overhang and drip). That portion of the order is affirmed. In their brief, respondents raised no objection to the prescriptive easement for appellants to maintain the fence. That portion of the trial court order is affirmed. See Melina v. Chaplin, 327 N.W.2d 19, 20 (Minn. 1982) (issues not brief on appeal are waived). On remand, all easements should, however, be modified to the extent required in light of the boundary line established in the new trial.

 Affirmed in part, reversed in part, and remanded for new trial.

 SHORT, Judge (concurring specially).

I concur insofar as the majority opinion reverses and remands for a new trial. The trial court's boundary line findings are without evidentiary support. In addition, the trial court misapplied the law for establishing prescriptive easements. See Kenney v. Webb, 352 N.W.2d 848, 849 (Minn. App. 1984) (holding prescriptive easements must be established by clear and convincing evidence). Under these circumstances, I would reverse the trial court's findings of fact, conclusions of law and order, and remand for further proceedings.