OPINION
¶ 1 Plaintiffs Thomas E. Brown Jr. and Marilyn R. Brown (the Browns) appeal the trial court’s judgment rejecting their boundary by acquiescence claim and quieting title of real property to Defendant Lee Jorgen-sen. The Browns also appeal the award of costs, the partial denial of their motion for summary judgment, and the denial of their post-trial motion to amend their pleadings. We affirm but vacate the award of costs.
BACKGROUND
¶2 The Browns own real property (the Brown Parcel) located in Summit County. The Browns took title to the Brown Parcel in 1971. However, other members of the Brown family have continuously owned the parcel since the 1940s. Jorgensen owns real property (the Jorgensen Parcel) adjacent to and to the southwest of the Brown Parcel and has maintained ownership of his parcel since 1979. The preceding owner of the Jor-gensen Parcel, Tracey Land & Livestock Company, used the parcel to raise livestock.
¶ 3 Located near the northeastern border of the Jorgensen Parcel is a fence (the Fence) that runs roughly along the southern border of the Brown Parcel. Sometime between 1943 and 1946, Thomas E. Brown Sr. and other Brown family members constructed the Fence. Although some of the Fence is located on the Brown Parcel, the Fence crosses onto the Jorgensen Parcel along a hillside above an irrigation ditch. The Fence separates a strip of land of approximately seven acres from the Jorgensen Parcel. This strip of land (the Subject Property) is the subject of this litigation. Since the Fence was erected, the Brown family has used the Subject Property and periodically maintained the Fence.
¶ 4 In 1971, the Browns hired a company to prepare a site plan to construct a home on the Brown Parcel. Although the site plan identified a property line different from the Fence line, the Browns built a home on their parcel and continued to use the Subject Property. In 1994, in anticipation of selling his parcel, Jorgensen commissioned an informal survey of the Jorgensen Parcel scaled from an aerial photo. This survey indicated that the property line was not the Fence line and that the property line actually cut through the Browns’ home.
¶ 5 In July 1999, Jorgensen sent a letter to the Browns demanding removal of the part of the Fence located on the Jorgensen Parcel. In response, the Browns commissioned a survey of the Brown Parcel. The results confirmed that Jorgensen’s 1994 survey was erroneous as to the property line cutting through the Browns’ home, but the survey correctly indicated that the Subject Property was part of the Jorgensen Parcel.
¶ 6 Thereafter, in 2001, the Browns filed an action to quiet title to the Subject Property, claiming ownership based on the doctrine of boundary by acquiescence. The trial *1256 court 1 denied the parties’ motions for summary judgment, but granted the Browns partial summary judgment, holding that they had satisfied some of the elements of the doctrine of boundary by acquiescence.
¶ 7 Trial was held on the remaining elements. After trial, the trial court found that the parties did not mutually acquiesce to the Fence as the boundary line, an essential element of the doctrine of boundary by acquiescence, and quieted title of the Subject Property to Jorgensen. The trial court also awarded court costs to Jorgensen pursuant to rule 54(d) of the Utah Rules of Civil Procedure. See Utah R. Civ. P. 54(d). The Browns now appeal.
ISSUES AND STANDARDS OF REVIEW
¶ 8 The Browns assert several claims on appeal. First, the Browns argue that the trial court erred by holding that there was no mutual acquiescence in the Fence as the boundary between the Brown and Jorgensen Parcels.
2
A determination of acquiescence “is reviewable as a matter of law.”
Argyle v. Jones,
¶ 9 Second, the Browns argue that the trial court should have granted summary judgment in their favor. Specifically, they contend that the trial court erred by denying their motion to strike Jorgensen’s affidavit in opposition to their motion for summary judgment because the affidavit did not comply with rule 56 of the Utah Rules of Civil Procedure.
See
Utah R. Civ. P. 56. “A trial court’s decision to grant or deny a motion for summary judgment is a legal one and will be reviewed for correctness.”
Salt Lake City v. Silver Fork Pipeline Corp.,
¶ 10 Third, the Browns argue that the trial court erred by denying their motion to amend the pleadings to include the claim of prescriptive easement. “The [trial] court’s decision to allow [or deny] amendment of the pleadings is reviewed for ‘abuse of discretion resulting in prejudice to the complaining party.’ ”
Savage v. Utah Youth Vill.,
¶ 11 Fourth, the Browns argue that the trial court erred in awarding costs to Jorgensen because he failed to timely file a verified memorandum of costs in violation of rule 54(d)(2) of the Utah Rules of Civil Procedure.
See
Utah R. Civ. P. 54(d)(2). Although the determination of the amount of allowable costs is generally within the sound discretion of the trial court, compliance with the procedure outlined in rule 54(d)(2) is mandatory and “leaves no discretion to the court; therefore, we review this decision for correctness without deference to the trial court’s conclusion.”
Lyon v. Burton,
¶ 12 Fifth, the Browns argue that the trial court’s judgment is overly broad in that it purports to preclude future claims against the Subject Property and that the judgment is therefore incompatible with the doctrine of res judicata. The issue of “whether res judi-cata bars an action presents a question of law[,] which we review for correctness.”
Massey v. Board of Trs. of the Ogden Area Cmty. Action Comm., Inc.,
*1257 ANALYSIS
I. Mutual Acquiescence
¶ 13 The Browns argue that the trial court erred in concluding that “[t]he [F]enee was not intended as a boundary line demarcating the [parcels]” and that “[t]here was no mutual acquiescence in the open boundary line of the [F]ence.” In support of their argument, the Browns assert that Jorgensen did not object to the Fence until several years after he acquired his parcel, that he treated the Fence as the boundary by never occupying any part of the Subject Property, and that he acquiesced to the Fence as the boundary line via his silence.
¶ 14 The party seeking to establish boundary by acquiescence must prove “(i) occupation up to a visible line marked by monuments, fences, or buildings, (ii) mutual acquiescence in the line as a boundary, (iii) for a long period of time, (iv) by adjoining landowners.”
RHN Corp. v. Veibell,
¶ 15 Various landowner activities may provide evidence of acquiescence in a visible line as a boundary, such as “[occupation up to, but never over, the line,”- or “silence, or the failure of a party to object to a line as a boundary.”
Id.
at ¶ 25. Although acquiescence in a boundary line may occur through a party’s silence or failure to object and does not require an explicit agreement,
“recognition and acquiescence must be mutual,
and both parties must have knowledge of the existence of a line as [the] boundary line.”
Argyle v. Jones,
1116 In the instant matter, although the Browns subjectively believed that the Fence was the property line, they never actually communicated their belief to Jorgen-sen, either by word or action. Therefore, there was no “actual acknowledgment ... that the parties treat the [F]ence as the common boundary.” Moreover, “ ‘[t]he mere fact that a fence happens to be put up and neither party does anything about it for a long period of time will not establish it as the true boundary.’ ”
Argyle,
¶ 17 Additionally, “[fjrom the initial recognition of boundary by acquiescence in Utah, courts have recognized the importance of the purpose of a fence.” Id. at ¶ 10. In this matter, the trial court found that Jorgensen’s predecessors “ran livestock on the land” and that the Browns and their predecessors also “used [their] property to graze cattle and sheep,” among other uses. The trial court *1258 concluded that “the purpose of the [F]ence was to contain livestock and keep grazing livestock of [Jorgensen’s] predecessor owner from the Brown property” and that “[t]he [F]ence was not intended as a boundary line demarcating the property.”
¶ 18 Because acquiescence is such a highly fact-dependent determination, we hold that the trial court did not err in concluding that the parties did not mutually acquiesce to the Fence as the boundary. As a result, the Browns failed to establish all the necessary elements of boundary by acquiescence.
II. Motion to Strike Jorgensen’s Affidavit
¶ 19 The trial court granted the Browns partial summary judgment, ruling as a matter of law that they satisfied some of the elements of the doctrine of boundary by acquiescence. The Browns claim that their motion for summary judgment should have been granted outright because the trial court erred in admitting Jorgensen’s affidavit included in his opposition to the motion for summary judgment. The Browns argue that Jorgensen’s affidavit contains inadmissible evidence including his “personal opinions, conclusions, and speculations, as opposed to allowable specific statements of fact as mandated by the Utah Rules [of Civil Procedure].”
See
Utah R. Civ. P. 56(e) (“Supporting and opposing affidavits shall be made on personal knowledge[ and] shall set forth such facts as would be admissible in evidence. ...”). “[T]he interpretation of a rule of procedure is a question of law that we review for correctness.”
Oliphant v. Estate of Brunetti, 2002 UT
App 375, ¶ 8,
¶ 20 The “major purpose of summary judgment is to avoid unnecessary trial by allowing the parties to pierce the pleadings to determine whether there is a genuine issue to present to the fact finder.”
Reagan Outdoor Adver., Inc. v. Lundgren,
¶ 21 Although Jorgensen’s affidavit does contain inadmissible hearsay, which appears to have been properly disregarded, the affidavit also contains statements from Jor-gensen’s personal knowledge concerning his recollection of events regarding the Subject Property that dispute the Browns’ contention that the parties acquiesced to the Fence as the boundary line. Thus, Jorgensen’s affidavit does not, as a matter of law, violate rule 56(e). See Utah R. Civ. P. 56(e).
¶ 22 Furthermore, as disputed issues of fact existed at the time the trial court considered the motion for summary judgment and as determining acquiescence is a highly fact-dependent question, the trial court did not err in partially denying the Browns’ motion for summary judgment. See Utah R. Civ. P. 56(c) (stating that a motion for summary judgment is only granted if “there is no genuine issue as to any material fact and ... the moving party is entitled to a judgment as a matter of law”).
III. Rule 15(b) Motion to Amend Pleadings
¶ 23 The Browns also argue that the trial court erred by denying them rule 15(b) mo *1259 tion to amend the pleadings to include a claim of prescriptive easement, even though their motion to amend was filed over two months after the trial concluded. See Utah R. Civ. P. 15(b). The Browns argue that each of the elements necessary for the claim of prescriptive easement was established at trial, even though they never mentioned or implied that they were seeking relief under the doctrine of prescriptive easement, and that Jorgensen impliedly consented to trying the claim of prescriptive easement.
¶ 24 The trial court determined that it did not “view [the] trial as one where the parties agreed, explicitly or implicitly, on a trial concerning prescriptive easement or any other cause of action other than title under boundary by acquiescence.” The trial court noted “[t]hat the phrase ‘prescriptive easement’ was not [even] utter[ed] during the trial ... and it certainly was not briefed [ ]or argue[d], and the court did not make its decision based on [that] doctrine.” The trial court denied the Browns’ motion and concluded that the Browns had ample opportunity to amend them pleadings much earlier and that “it would be fundamentally unfair to allow [the Browns] to now seek recovery of a different sort[ and] on a different cause of action.”
¶ 25 Although some of the elements of the two doctrines overlap, the critical element of adverse use, under prescriptive easement, was not argued or presented to the trial court. Throughout the trial, the Browns claimed that the parties mutually acquiesced or recognized the Fence as the boundary, not that the Browns were notorious and adverse in their use of the Subject Property. 3 As a result, Jorgensen could not expressly or impliedly consent, under rule 15, to trying the claim of prescriptive easement. See Utah R. Civ. P. 15.
¶26 While rule 15 “permits the amendment of pleadings by leave of court, and the rule is to be liberally construed so as to further the interests of justice[,] ... the rule is to be applied with less liberality when the amendments are proposed during or after trial, rather than before trial.”
Girard v. Appleby,
IV. Memorandum of Costs
¶27 “Rule 54(d) provides that costs are awarded as of course to a prevailing party and that the trial court is to assess costs based on a verified memorandum of costs, which must be filed by the successful party within five days after entry of judgment.”
Valcarce v. Fitzgerald,
V. Res Judicata
¶ 28 In its judgment, the trial court stated that
[flee simple to the [Subject Property] should be and the same is hereby quieted [to Jorgensen] against and free and clear *1260 of all boundary by acquiescence and all other claims of [the Browns] and of all claims of all other persons who may claim, by and through or under [the Browns] or either of them.
The Browns argue that this language of the trial court’s judgment is overly broad in that it purports to preclude future claims against the Subject Property and that the judgment is therefore incompatible with the doctrine of res judicata. “The doctrine of res judicata serves the important policy of preventing previously litigated issues from being reliti-gated. Res judicata encompasses two distinct doctrines: claim preclusion and issue preclusion.”
Snyder v. Murray City Corp.,
¶ 29 “Generally, claim preclusion bars a party from prosecuting in a subsequent action a claim that has been fully litigated previously.”
Id.
at ¶ 34 (quotations and citations omitted). Although “[preclusion advances judicial economy by preventing the unnecessary relitigation of claims and issues[,] ... due process concerns are present ... when the party sought to be precluded was not an actual party in the first lawsuit.”
Brigham Young Univ. v. Tremco Consultants, Inc.,
¶ 30 Here, we are not presented with a subsequent suit seeking preclusion against a party concerning the claims in this matter. Any argument concerning future hypothetical parties and claims may be presented to the trial court only when ripe and in their own due course. A party “generally must assert his own legal rights and interests, and cannot rest his claim to relief on the legal rights or interests of third parties.”
Warth v. Seldin,
¶ 31 We conclude that the language used by the trial court in its decision is effective against the parties and their claims to title of the Subject Property. The trial court’s judgment does not preclude nonparties from making their own claims against the Subject Property or Jorgensen. Nor does the judgment violate the doctrine of res judicata.
CONCLUSION
¶ 32 We hold that the trial court did not err in concluding that the parties did not mutually acquiesce to the Fence as the boundary line. The Browns have therefore failed to establish all the necessary elements of boundary by acquiescence. We hold that Jorgensen’s affidavit does not, as a matter of law, violate rule 56 and that the trial court did not err in denying part of the Browns’ motion for summary judgment. Furthermore, we conclude that the trial court did not abuse its discretion in denying the Browns’ motion to amend their pleadings. Because Jorgensen failed to file a timely verified memorandum of costs, the award of costs is *1261 hereby deleted from the judgment. Additionally, we hold that the Browns’ argument of claim preclusion under the doctrine of res judicata is without merit.
¶ 33 Accordingly, we affirm the trial court’s judgment, but vacate the award of costs.
¶ 34 I CONCUR: CAROLYN B. MeHUGH, Judge.
¶35 I CONCUR, EXCEPT THAT AS TO SECTION I, I CONCUR ONLY IN THE RESULT: GREGORY K. ORME, Judge.
Notes
. Judge Robert K. Hilder presided over and decided both parties' motions for summary judgment. Later, Judge Bruce C. Lubeck presided over the bench trial and issued final judgment in this matter. For ease of reference, we refer to both of the judges as "the trial court.”
. The Browns also argue that the trial court erred by finding that the Browns did not occupy the Subject Property "up to a
visible line
marked by monuments, fences, or buildings"—the first element of boundary by acquiescence.
Argyle v. Jones,
. In fact, prescriptive easement and boundary by acquiescence are antithetical doctrines. The former requires notorious and adverse use while the latter requires mutual recognition and acquiescence to the boundary line.
See Valcarce v. Fitzgerald,
. To assert the doctrine of claim preclusion, the party seeking preclusion must establish three elements:
First, both cases must involve the same parties or their privies. Second, the claim that is alleged to be barred must have been presented in the first suit or be one that could and should have been raised in the first action. Third, the first suit must have resulted in a final judgment on the merits.
Snyder v. Murray City Corp.,